I'm trying to implement Google oAuth example witch is compiling but I want to take it one step further and not have client ID and secret hardcoded.

I have a service that gets the content from a settings page and are initializing it inside the builder.

public class RegisterSiteServiceComposer : IComposer
{
    public void Compose(IUmbracoBuilder builder)
    {
        builder.Services.AddScoped<IIBDContentService, IBDContentService>();
        builder.AddGoogleAuthentication();
    }
}

But how do I inject that into so it can be used from the AddGoogleAuthentication().

.........
// The scheme must be set with this method to work for the back office
var schemeName =     backOfficeAuthenticationBuilder.SchemeForBackOffice(GoogleBackOfficeExternalLoginProviderOptions.SchemeName);

OAuthSettings oAuth = _contentService.GetOAuthSettings("Google", "user");
................

Have used this https://docs.umbraco.com/umbraco-cms/tutorials/add-google-authentication for implementing all the code.

Is this possible and if so how.

Normally I would do something like this:

    public partial class SomeController : UmbracoAuthorizedJsonController {
        private readonly IBDContentService _contentService;

        public SomeController (IBDContentService contentService)
        {
            _contentService= contentService;
        }

        public void someRoutine() {
            ........
            OAuthSettings oAuth = _contentService.GetOAuthSettings("Google", "user");
           .......
       }
}