The application could not be launched because the Developer App Certificate is not trusted. Same here. Can't sign mobile app builds from xCode.

@DTS Engineer I would also like to know if what @danishd said is possible.

I am having a similar issue. @grennis were you able to at least generate a JWT using the https://appleid.apple.com/auth/token API? I haven't been able to and I assume it's because my .p8 key doesn't have "Apple Sign In" since we disabled the old version of the app on the old team.