As long as the training session is in the "Planning" stage, it can be viewed in the participant roster. Participants can be added.
If invitations to the training session have already been sent, go back one step in the workflow to add participants.
Procedure in the FM Portal
Path to the starting point: Infrastructure Building Management - Training Administration - Training Courses
Open the training session to which you want to add participants.
Click the "Add to Planning" button.
Now go to Participant Management to add people.