Optional state query parameter

I don't have a clear idea of the architecture of the system you are working with - which environment in the linked diagram is the drupal site - but if you need to add options to each request, you can implement a collaborator. In this case you want to implement an OptionProvider where you implement your logic for generating the additional option on the request.

We did this in ClientCredentialsOptionProvider for scopes in #3157501: Add Scopes to ClientCredentials Grant Type → and you can see that implementation as an example at ClientCredentialsOptionProvider.

Automatically closed - issue fixed for 2 weeks with no activity.