Granting admin rights to user (self hosted)

New to Vikunja, still trying to connect emotionally to my wild, slender South American camelid native friend.

Just created the first user ‘admin’ but didn’t get admin rights.
Trying to resolve this with:
docker exec vikunja-app /app/vikunja/vikunja user set-admin 1 --admin as per the online documentation, but I get: unknown flag: --admin.

What am I missing?

Do you have a Vikunja Pro license?

No, I don’t. Running it for my home lab