Support Key Flow Authentication

[thorbenbelow]

Is your feature request related to a problem? Please describe.

Service Account Access Tokens will be deprecated effective December 17, 2025.
Currently this seems to be the only authentication method integrated in this plugin.

Describe the solution you'd like

Support the key flow authentication method.

Describe alternatives you've considered

n/a

Search

• I did search for other open and closed issues before opening this.

Code of Conduct

• I agree to follow this project's Code of Conduct

Additional context

No response

[PatrickKoss]

Hey @thorbenbelow

Have you tried using the flag --dns-stackit-service-account and --dns-stackit-project-id as the Readme states it?