How to automatically set OAuth 2.0 Access Token as variable

I have managed to created three tokens (DEV, STAGING, PROD) :

But how to invoke them (the tokens) dynamically when I change the testing environment (I have also three env: DEV, STAGING, PROD in Postman).

It looks like that these token names are static : here is an example : I choose the testing env “01-PROD” on the top right but the token that been used is still “TOKEN DEV” !