WEB UI LOGIN: redirect_uri_mismatch / G+ API deprecation

[bergalytics]

(I've swapped my domain out for "example.com" in the below...)

When I try to login through the web UI (example.com/portal/), I get a URI mismatch error:

"The redirect URI in the request, https://example.com/portal/auth, does not match the ones authorized for the OAuth client."

I can't add in my redirect URI because a client id and secret is hardcoded in server/ui.go for a project I don't have access to:

var oauthConf *oauth2.Config = &oauth2.Config{
	ClientID:     "523939206127-3pr1qbrn0g78l6r9nu10l733q9obgn0t.apps.googleusercontent.com",
	ClientSecret: "zKY48Os4L8xKAuQoiBFqrLkW",
	Scopes:       []string{"email", "profile"},
	Endpoint:     google.Endpoint,
}

When I swap this out for a project I own with the redirect uri setup then retry, I get an error that the legacy Google Plus API isn't enabled even though I've enabled the API in the console for that project.

I'm assuming you've hardcoded these credentials in because the hardcoded project (523939206127) has the legacy Google Plus API enabled and you're no longer allowed to enable the API for new projects (error below). If that's the case, how can I get around the redirect URI mismatch if I cannot add the URI to the project in the console?

"could not fetch Google profiles: googleapi: Error 403: Legacy People API has not been used in project 577030841713 before or it is disabled. Enable it by visiting https://console.developers.google.com/apis/api/legacypeople.googleapis.com/overview?project=577030841713 then retry. If you enabled this API recently, wait a few minutes for the action to propagate to our systems and retry., accessNotConfigured"

I've tried accessing the link in the error but it no longer exists as the API is legacy.

[seftimie]

@sinexu / @Laremere any solution for this issue? I recently run a test/deployed on GCP the solution and this issue is still ON.

Is this code an issue?: https://github.com/google/web-api-gateway/blob/master/server/ui.go#L60 ?
How can I overwrite CliendId and ClientSecret after deploying the solution?
ClientID: "523939206127-3pr1qbrn0g78l6r9nu10l733q9obgn0t.apps.googleusercontent.com",
ClientSecret: "zKY48Os4L8xKAuQoiBFqrLkW",

is there any mechanism for this? Because from: https://accounts.google.com/signin/oauth/error i get:

Authorisation Error
Error 400: redirect_uri_mismatch
You can't sign in to this app because it doesn't comply with Google's OAuth 2.0 policy.
If you're the app developer, register the redirect URI in the Google Cloud Console.

Thanks