Set/update configuration variable in workfloe

Hi,
Is it possible to update the value of a configuration variable in a workflow?

If not possible any idea of how to do the following:

What I am aiming for is to take an incoming webhook with a oauth parameter and store it in a configuration variable for referencing in a custom oauth workflow to proceed and ask for token

When that is done I also want to store the token and refresh token so it’s available for all users when they query a resource