The second step in setting up your transactional SMS messaging is to trigger an API call to retrieve all of the active lists associated with your short code. Be sure to have authenticated yourself before moving to this next step. Follow the below steps to test this in Postman or a REST application of your choice.

1. Open https://api.listrak.com/sms in a tab.
2. Navigate to the phonelist tab.
3. Then Get Collection of SMS Lists.
4. Copy the relative Get Collection of SMS Lists URL from the right-hand side of the page.

5. Navigate to Postman.
6. Paste the relative URL in the address bar.
7. Add the short code ID from the previous article to the URL.

8. Click Send.

You have now received all active lists associated with your short code. Copy the List ID that you would like to use for set up and testing.