Gcp cloud run health monitor post request authentication

Hi Team,
iam trying to loadbalance vertex ai endpoints, now iam trying to perform health monitor ,to check gemini model response, i configured below:

https://www.googleapis.com/auth/cloud-platform RoundRobin true 1 429 500 502 503 504 true 30 10 30 POST /v1/projects/projectid/locations/{location-id}/publishers/google/models/gemini-2.5-pro:generateContent application/json {"contents":\[{"role":"user","parts":\[{"text":"hi"}\]}\]} 200

its not working as expected.
does authentication is taken care in http monitor?
how to substitute dynamically projectid and location in http monitor?
how to pass google access token in http monitor?
how to authenticate post requests to gcp cloud services say for eg:storage,secret manager ,…etc.
any limitations in http monitor config?
is above config valid?
any suggestions please

Hi @chandra_kanth_major, welcome to the Apigee community! It is great to have you here as a first-time poster :waving_hand: we’ve noticed your question hasn’t been answered yet, but we’ll keep it on our radar and reach out to others in the community to chime in.

Hi @chandra_kanth_major - Are you using Apigee for this? If not then better to ask in the AI forum or whatever LB you’re using..

any suggestion