Hi @Feenix73 are you asking whether you can assign a course based on enrolment into another course? If yes, you can certainly do this using Groups AND Enrolment Rules.

First create your group that captures all users enrolled (Subscribed) to course A (ILT) - don't activate or process it fully so you might want to leave out a rule or something else to prevent it from capturing your users until your Enrolment rules are in place; otherwise the users in your group will not be assigned once the Enrol rule kicks off ( a bit of a chicken & egg scenario).

Next, create your Enrolment rule based on this new group where you can assign course B (optional course).

Last, go back to your group and finish the set-up and “process” it. This will capture all users currently assigned in the first course and the enrolment rule will assign course B to them.

NOTE about the notion of an “optional” course...Docebo has no concept of optional courses so you’ll need to decide whether you’ll want this course to sit on user plans for certain amount of time after which you can manually un-assign them if they haven't completed, or you can decide on some other method.

That optional point is huge, make sure to vote it up!

if it’s not in a learning plan and is just being added as a course for them to know then it is just a matter of positioning and should be fine.