The StarkNet EDU team has assembled a Postman workspace that includes relevant API calls for developing and testing your Cairo code in various environments. I recommend the desktop version: https://www.postman.com/downloads
Once downloaded search in the search bar and select the workspace “starknet-edu” . Verify the id is correct: 5cf35dcd-9230–4e4a-aa1e-c52a4e910d02(info icon next to “workplace settings”). Notice the environments drop down on the top right:
Select the ellipses(three dots) on the right of each collection. Then select “create fork”. Navigate to the Environments tab on the left nav and do the same for the environments.