You have already set it up to be dynamic. Using square brackets ‘[ ]’ will create a dynamic key value pair. Throughout your website you can now call this API and use a different shop_name each time by using a dynamic expression.
Am i misunderstanding what you are asking?
@cmarchan Okay, I’ve deleted it and put in the url.
How can I now change it then in the workflow tab?
Where can I insert the dynamic value for shop_name so that this will be inserted in the URL?
You have selected to use this API as an action, so you’ll be able to use it as an action in your workflow tab. It will appear with the name you gave it - Shopify Exchange Token. Once you select it as an action, you’ll be able to specify the Shop Name dynamically.