https://robokassa.com

Robokassa - simple solutions for accepting payments and organizing online sales. "Robocheki" is a free online cash register! Use our cash-register to punch your electronic checks.

To use the plugin, you must be a registered Robokassa user.

1. Registration and start of accepting payments - https://robokassa.com/content/nachalo-raboty.html
2. Connecting payment notifications - https://robokassa.com/content/opoveshchenia.html

Feature

• cost can be fixed or selected from a range
• can use password or button to bypass the payment
• recurring payments (additional plugins from recommendations are required)
• support for the missed period surcharge function from enrol_yafee

Recommendations

• To enroll in courses, use my plugin that supports time limits for recurring payments "Yet another Enroll for payment" enrol_yafee
• For the control task, use the plugin I patched at the link mod_gwpayments
• To limit availability, use the plugin I patched at the link availability_gwpayments
• Plugin for viewing reports and for recurrent payments support - report_payments

No technical support in the comments here. To get support, please open an issue on Github.