It seems the wrong file is mentioned for registering the key with the user in the context of yubico cloud login.

When using the file `~/.yubico/authorized_keys` to add `<username>:<key-id>`, I get the following error in debug mode:
```
debug: pam_yubico.c:1009 (pam_sm_authenticate): pam_yubico version: 2.27
debug: pam_yubico.c:1024 (pam_sm_authenticate): get user returned: <user>
debug: pam_yubico.c:221 (authorize_user_token): Dropping privileges
debug: pam_yubico.c:1149 (pam_sm_authenticate): No tokens found for user
debug: pam_yubico.c:1337 (pam_sm_authenticate): done. [User not known to the underlying authentication module]
```

Whereas following the instructions from https://github.com/Yubico/yubico-pam?tab=readme-ov-file#individual-authorization-mapping-by-user, the login succeeds. It seems the default file is `<sub>/.yubico/authorized_yubikeys` and not `</sub>/.yubico/authorized_keys`.