The issue you are having is not permissions on the container app, it is permissions on the container registry you are trying to pull the image from. This error:
The client '******@anyonsys.com' with object id '6764a3b4-0c48-4b23-9bdd-d4e62af3c3f6' does not have authorization to perform action 'Microsoft.ContainerRegistry/registries/listCredentials/action' over scope '/subscriptions/7e0adb77-2026-4e91-84eb-99bd94f80983/resourceGroups/rg-thunderhead/providers/Microsoft.ContainerRegistry/registries/thunderhead' or the scope is invalid. If access was recently granted, please refresh your credentials.
States that you do not have permission to get credentials to access the container registry called "thunderhead"