This tab displays influencers requesting to close the collaboration after fulfilling the agreement and adding the links to show where they have posted content.
Influencers are not allowed to close collaborations, only you, the brand.
So, when influencers feel they have completed the work required, they have the option to send you a request to complete and close the collaboration.
Make sure you’re happy with their work, all relevant links have been submitted and ,if it all checks out, accept their request, complete the collaboration and rate the influencer.
Make sure that's your final decision as you cannot re-open a collaboration after completing it (but you can always add links to the Report for more accurate results).
On the top right of your influencer area, there's always a collaboration status update (deadline's days left, confirmations, agreement sent, waiting on a reply, ...). Be sure to check it out for extra information on the status of your collaboration with them.