@dr.reinhardt There are multiple ways to enroll user into many courses.

1. Enroll users to multi courses via CSV file - You can find the .csv file option (Manage Enrollment) in course management area. Download the sample file and fill the required details (Username, level, course code or ID) the remaining fields are optional. Before enroll user via csv, ensure that the deadline has been enabled in the course management settings. (CSV file does not works properly for “active_until” format).
2. Course Management tab: Select the courses manually in Course Management area and click “Choose Option” bottom right corner of the row and select “Enroll user” option to enroll them into multiple courses.

The below KB URL helps you understand how to enroll users in multiple cases:

Enrolling Users in Courses and Sessions via CSV Files – Docebo Help & Support

Morning @dr.reinhardt 

As @Baskaran venugopal said, there’s multiple ways.

I tend to use a third way when adding an individual or two that needs enrolled in multiple courses.

Navigate to the User Management area, you get to select the user/branch/groups and then select the courses.

I’ve grabbed the key screens and attached them here. Hope it helps.

@Baskaran venugopal , @AngeWi      You solved my problem!

Have a great day!