See link for the WHAT.
Use the existing API endpoint common for all 4 ALMs: POST api/alm_settings/validate?key=xxx
This endpoint will return an empty 200 code if everything is alright, or a 400 code with a message as plaintext detailing what issue is detected.
To validate that Azure DevOps is properly configured, on the endpoint implementation, we want to verify the connectivity, the authentication, and the permissions. Unfortunately, ADO Server API does not allow us to do anonymous call, nor a specific endpoint to validate the authentication specifically. So we will reuse the onboarding Check PAT implementation.
We can now align the UI with the other 3 ALMs, using the common Components.