In principle, you appoint a file coach per file (i.e. one internship for one student).
In the student's file, use the relevant step from the step-by-step plan, or create a new activity. The option for this can be found under the 3 vertical dots at the top right of the screen.
Choose the type of file supervisor and choose the name of the teacher who should fulfill the role.
But if an entire group of students has the same supervisor, it is not efficient. You can therefore also provide a group of students with a file supervisor.