docker login says unauthorized (401)

docker login registry.reelhost.app says "unauthorized", or docker compose pull says access denied or "Sign in first".

• Username is the email address exactly: the one the free key was sent to, or the email on your license.
• Password is the key, starting with RH-, copied without spaces. It isn't a password for your account.
• Sign in as the same user that runs Docker: if you use sudo docker compose, sign in with sudo docker login.
• Lost the free key? Ask again on reelhost.app: you get the same key. Lost your license key? Use Find my key.
• A refunded or deleted license no longer signs in. Ask for a free key, or write to us from your account.