Hi there!!
You’re neither the owner nor a collaborator of gnome-3-38-2004-sdk, so it seems correct that you have no permissions to upload or release new revisions to it.
Having access to the LP repo has no bearing on store permissions; Launchpad builds are connected to the store using the credentials of an existing collaborator to the snap, that’s how that worflow is working.
As for the Launchpad upload failure, it’s likely the credentials have expired; there’s a button the person who manages those builds (Ken or Seb) can click to refresh credentials.
Give this a try and/or have Ken/Seb try it, and please let us know if it still doesn’t work.
- Daniel