The only thing you have to do here is add your PayPal address in "PayPal payment email" field and set "Sandbox (test): No" to start taking Live payments.
Below you can see explanations of all available settings for this payment method.

To set up PayPal please log in to the back end and go to Dashboard > Payment methods > PayPal.

Title: - the name of the payment method that the customers will see at the front end. It may be a good idea to change it to PayPal/Credit and Debit cards
Published: Yes/No - set to Yes to have this payment method available at front end. Set to No to disable it.
Description: - text entered here will be shown as a Tool tip when customer mouse over the payment method at the front end booking form.

Configuration tab: 
PayPal payment email: - this is the most important setting. Type in your own PayPal email address here - this is where the money for paid booking will go.
Accept only verified buyers?: Yes/No - set to Yes to accept payments from only Verified PayPal buyers. PayPal uses verification process for every PayPal account to make sure that there is less fraud with their payment service. Default setting is "No" because there are many people who don't bother to Verify their PayPal account but still use it to make secure payments.
Merchant Sandbox Email: - type in your Sandbox (Test) PayPal email. To get a Sandbox PayPal account you have to register at https://developer.paypal.com/  - this is different from your normal PayPal account and has to be done separately. It is optional to have Sandbox account, we have done all the testing necessary with payments, it will only help you if you want to run some test bookings for yourself.
Sandbox (Test): Yes/No - with this setting you switch between Live and Test PayPal transactions. "Sandbox: Yes" is the setting to start getting Live payments for bookings.
Minimum amount: - use integer to type Minimum amount here. Under this minimum amount PayPal will not be available as payment method at the booking form. Blank or 0 means that there is no Minimum amount required for transactions.
Maximum amount: - opposite the Minimum amount above with Maximum amount you set up a limit for a payment. 
Fee per transaction: - a flat amount to be added to the Total as a Fee that you have for using this payment method. PayPal charges $0.39 (different for different currencies and countries) for each transaction so you can recover this charge with this setting here.
Tax in %: - use if you need to add Taxes separately to each booking and based on Payment method.
VAT in %: - use this setting if you are European company and you have to add VAT (Value Added Tax) to your transportation services.

Prepayment % - use this setting to set up a Deposit % for a booking. This % will be requested via PayPal payment and the rest will be Due to the driver or other offline payment method. Blank field or 100 means that the whole amount of Total will be processed through this payment method.
Order status for pending transactions: Waiting/Accepted/Rejected/Archived - this setting tells the system what would be the status of bookings with incomplete payment. The system will send Order notification email based on this setting as well, the order status will be changed according the setting you have here. Default status is Waiting - Admins, Drivers and customers will receive Order notification email with Waiting status and Admins can contact the customer to arrange Order payment outside the system and change the status of the order manually to Accepted.

Order status for Successful transactions: Waiting/Accepted/Rejected/Archived - PayPal will notify the system if a payment has been successful and the system will change Order status to what you have set up here. Default is Accepted but you can change this to Waiting if you manually have to check each order and Accept or Reject it. If you Reject an Order refund will not be automatic so you have to make sure that you manually refund the customer through your PayPal account dashboard.
Order status for Failed transactions: Waiting/Accepted/Rejected/Archived - PayPal will notify the system if a payment has failed and the system will change Order status to what you have set up here. Default is Rejected which will not block off the car for the selected Date/Time but Admins will still receive notification so they can contact the customer for more details and capture payment outside the system.
Send Email for Pending status: Yes/No - this setting is to send an email notification to the customer if payment is Pending (not completed). Admins will receive the email even if the setting is "No".
Send Email for Approved status: Yes/No - this setting is to send an email notification when payment is successful. Default is "Yes" and the system will automatically email all parties with order details.

Convert currency: Yes/No - this setting is only for countries which currency is not supported by PayPal but company owners have PayPal accounts in different (supported) currency eg. booking form is set to Peruvian Sol (not supported by PayPal) but the company has PayPal account in USD (supported by PayPal). When "Convert currency: Yes" the system will convert Peruvian Sol to USD and will send USD equivalent of Total to PayPal for payment processing.
Convert to: List of all PayPal supported currencies - select the PayPal currency that you need conversion to.
Conversion index: - a numerical value of the currency conversion index eg. Peruvian Sol trades for 0.30 USD so you type in "0.30" (always use "." instead of "," throughout the system back end). Total will be converted to USD and USD amount will be sent to PayPal. Note: currency index is this case is static, make sure that you change the index if currency trading changes significantly.

Use in App?: Yes/No - this setting is to activate PayPal in the DriveNot app. Setting to "Yes" will not activate PayPal in the app instantly, you will have to apply with PayPal to have your account enabled for mobile payments. Contact us for more details and help with this setting. You will also have to apply for DriveNot mobile app inclusion of your company through the back end > Dashboard > DriveNot network > Apply to join DriveNot mobile app.
Debug: Yes/No - this setting is to record transaction details in case there is anything wrong with PayPal transactions. Contact us if you have problems with this payment method and we will help you Debug it.
Client ID (Sandbox) - client ID for Sandbox through the mobile app can be obtained through the normal Sandbox account.
Client ID (Production) - this ID is assigned to the PayPal account holder after the account has been approved by PayPal to accept Mobile payments. Contact us for more details and help.
Split payments enabled: Yes/No - this setting is used when you have Shared rides enabled in back end > Dashboard > Cars > Edit car > Car Shared?: Yes > PayPal refunds: Yes > Second purchase (%) and First payer refund (%). More information on Shared rides here.
API username: - obtain API username from your PayPal account. 
API password: - also provided through the API setting in your PayPal account.
API signature: - third security option provided to you when you set the Split payment API in your PayPal account.
More on how to get PayPal API credentials here: https://developer.paypal.com/docs/classic/api/apiCredentials/