Hey, you are right! There must be a possibility to enter the account name or sign in without the Posting Key in order to be able to accept the request, if the password was changed from the other side. It worked before, because it was on the Dashboard page and there was no login required.

Thank you very much for this important discovery! I will fix it now ;)

Update

It is fixed now and I was able to accept the request for @sw-test without signing in. There is now a new input field for the account name: