Backup not possible

Hello Community,
I installed the 2.7.1 version on a Raspberry 4 a few days ago. Runs very well. However, one very important function does not work - the backup. I get the message:

Error: failed to backup metadata: failed to download metadata snapshot: InfluxDB OSS-only command failed: 401 Unauthorized: read:authorizations is unauthorized

I have only one API - token in my inventory - I tried to clone it too. All without success.
After some research I got the hint for a so called ‘admin token’, but I don’t have it (or at least I don’t know where to read it).

The command
influxd recovery auth create-operator

did not bring success either: Error: bucket “authorizationsv1”: bucket not found

I can’t get any further… Please help me.