Prerequisite:

1. You'll need a Moodle installation that is visible on the internet. See https://ngrok.com/.
2. You'll also need to have a PayPal developer account and set up Sandbox accounts (at least 1 facilitator/business and 1 buyer account). For more information, see https://developer.paypal.com/developer/accounts/
3. Optional: Set up Moodle SMTP settings.
4. Set $CFG->usepaypalsandbox = true; in your config.php to use sandbox account for testing.

Test

1. As admin go to Site administration > plugins > Enrolments > Manage enrol plugins
2. Enable PayPal enrolment methods
3. Set "Paypal business email" to PayPal facilitator sandbox account. (Site administration ► Plugins ► Enrolments ► PayPal)
4. Go to an existing course (c1) and navigate to Enrolment methods (Course administration ► Users ►Enrolment methods)
5. Set Add method to "PayPal" and set "Enrol cost" to 1
6. Log in as a student and click on the course, then the "Send payment via PayPal" button
7. Confirm payment and click on the link to go back to your Moodle site.
8. Ensure you are enrolled in the course
9. Backup course and restore it as a new course
10. New paypal enrolment method should be created.