How to pass variable in to API URL?

How do i pass a variable in for a API URL?
Details:https://console.jumpcloud.com/api/v2/users/{Userid}/associations?targets=system_group
The {Userid} is the variable i need to pass to the API.

Thanks!

Should be double{{ and }} in that expression,can you check and come back to me

It didn’t work for me, is there any other way to pass a variable to the API?

I tried many ways including dynamic attributes but none of them worked.