Hi,
Say, you have two environments, one being NON_PROD & the other being PROD and you have two config files with some information in them about the respective environments.
In your NON_PROD file declare a variable named flag and give it a value of 1, same way, in your PROD file declare the variable named flag and give it a value of 2.
Then,
In your test case, you can have a do nothing step with multiple assertions checking the value of the variable flag and from there you can route based on the value of flag.
If flag = 1, go to Get Security token
If flag = 2, go to Web Service Execution step
You can use this assertion : Ensure property matches expression
Hope this helps.