If you set up a community when you published your course, it will be available to any students who join the community. However, if you set up the community after launching your course and already have students in it, there might be a case where those students are not added to the community.

Let's see how easy it is to add those students to the community.

Go to 'Communities' > select desired community > click 'Members' icon.

You can view the current members, which currently includes only one student. To ensure that all students are added to this community, simply click 'Add All Enrolled Students to Community'.

You will notice that the students enrolled in this course are automatically added. Now, they will have access to this community.

Always double-check that the students you want to be added to the community are indeed added.