c# – The right way to Used Google Play Unity Code from server to get participant data

I exploit this line of code to get the consumer server entry token in unity:

 PlayGamesPlatform.Occasion.RequestServerSideAccess(true, Callback);

the callback responds with a code. after that, I want to make use of this code to get participant info on the server aspect.

I have already got used access_token, id_token, and api_key from the google developer console. used many various settings however i all the time get 401 invalid authentication responses.

i exploit c# asp core on the server aspect however I feel I can use row HTTP request to get a response. i must know the best setup to ship the request to google api.

it is one setup that did not work.

   payload = await GoogleJsonWebSignature.ValidateAsync(request._googleTokenId,
                    new 
 GoogleJsonWebSignature.ValidationSettings()ForceGoogleCertRefresh = true });