Hallo,
in order to use the booster for SAP Build for Apps I created an IAS tenant for my BTP free tier account. But when accessing user management, I get a 404-error as seen in this image:

It seems that the application tries to call a webservice which results in a 404-error:

I didn't stumble over any solution to this but as a possible result, the user assignment via the booster also doesn't work. I actually have to add the users as administrators in the IAS tenant for I can't access the management of regular users as described.
Any hint or solution would be greatly appreciated.
Best regards, Alexander