If the API tells you how many records, or better yet, how many pages then you can do this:
1. Call the API once
2. Create a helper list with size = number of pages (or number of records/page size)
3. Iterate through the helper list with a FOR EACH loop
4. Within the for each, call the API and set the page_num = the sequence number of your for each loop
After this if you can do whatever you want, either process the records in the for each loop or add them to the end of a pre-defined list so you can process them when the for each loop completes.
If the API doesn't tell you how many records it's going to return, then that's truly unfortunate, but manageable. You can define a variable as a high number to start with to mimic the number of pages in step 2 above. But then, you can avoid calling the endpoint an unnecessary number of times by saving the latest number of records returned from the endpoint within your for each loop as a variable, and use an IF condition within the for each to only call the endpoint if the most recent number of returned records was > 0, or if the number of returned records is equal to the max page size if you know that information.
