You can find the topic 'Approval' on the left in the menu bar. Here, all requests for subscription arrive, but also submission assignments that need correcting or qualifications that must be assessed.
On the right of a request are an eye and/or a checkmark and cross. The eye means that it still needs to be corrected. Using the checkmark and cross you can allow the user to follow the learning activity or you decline the request. This can be the case when the requested activity isn't meant for the applicant.