For now I tried to solve this problem as follows. But I don't know if it will work because the time is long. Can you check?
I went to the Registered users section and went to the settings under the Manual Enrollment heading and made the registration period of 104 weeks so that the trainee will remain registered in the course for two years. At week 102 an email will be sent to the trainee and the enrolling trainer so that my moodle will need to take the course again.
