composer require fails with 401 or 403. What is wrong?

Composer cannot sign in to the private repository. Check, in this order:

1. The username is the email the license was bought with, which is not always your GitHub or work email. The password is the license key, without spaces.
2. The host is qalainau.privato.pub, exactly as in composer config --auth http-basic.qalainau.privato.pub "email" "key". Look in auth.json in the project and in ~/.composer/auth.json: an old entry there can win.
3. On CI or a server, the credentials have to be there too, in the COMPOSER_AUTH environment variable (see "How do I install a plugin on CI or a server?").
4. A refunded license is revoked and cannot install anything.

The quickest check: enter the same email and key on your account page. It tells you whether they are accepted and which plugins and versions they install.