This article will show you how to edit Payment Requests Email Template.
Navigate to Settings > Car Rental > Emails
Then go click on Payment Requests.
Here you will see three sections:
Emails for System Notifications
Scroll down to Email Settings and look for Payment Requests Email Subject and Payment Requests Email Text. Here is where you can edit the subject and the content of the email that will be sent out if you request for payment using the Payment Request button.
To know more about Payment Requests, please go to this article.