You need a PayPal account to test this Setup Log in to https://developer.paypal.com/developer/accounts/  and create one personal and one business accounts if you don't already have them (you change their password if you have some accounts there but you can't remember their passwords). Go to   https://developer.paypal.com/developer/applications Set the environment to Sandbox (using the toggle at the top) Click on the "create app" button from the "REST API apps" section Name your app "Moodle test" or whatever you like Choose a sandbox business account and then click on the "create app" button. At the next page, make note of the "Client ID" and "Secret" Log in to Moodle as admin Visit "Site administration > Plugins > Payment gateways > Manage payment gateways" and enable the PayPal gateway Visit "Site administration > Plugins > Payment gateways > PayPal" and enter PayPal's "Client ID" and "Secret" there Set the environment to 'Sandbox' Visit "Site administration > Plugins > Enrolments > Manage enrol plugins" and enable the "Fee" plugin Create a course Add the "Fee" enrolment method to the course and set a cost and currency for the enrolment Test Log in as a non-admin user Try accessing the course At the enrolment page, verify that you see the "Pay enrol fee" button Click on the pay button Verify that a modal opens with an option to pay the course fee by PayPal Verify that the PayPal option is already selected Click on the proceed button Verify that a new modal opens with some options. The number of options you see here depends on your PayPal account's country, but a simple "PayPal" button should be in the options Chose to pay by PayPal account Use a sandbox account to pay the course's fee (Read steps 11 and 12 now because you only have a limited time to follow them) Verify that after you finish the payment on the PayPal website, you see "Authorising the payment. Please wait..." message on Moodle Verify that clicking outside of the modal or the Escape key does not close the modal while it is authorising. The modal will be closed itself when the authorisation is finished. Verify that you are enrolled in the course