How to remove add-in in new Outlook

Hi, in old outlook I used https://aka.ms/olksideload to remove an Outlook add-in I'm developing. There is a big delay, but eventually the add-in is deactivated. In the new Outlook, this method still works. However, if I try to remove it using the menu provided in the new outlook client (apps>manage your apps>remove), it makes a request to https://teams.microsoft.com/api/apps/emea/beta/users/apps/entitlements/ (followed by an ID string), and I get the response 403 forbidden. It is difficult for me because I am not an admin, but what can I suggest our admin check out to allow the app remove privilege to work in the new Outlook? Thanks.