It depends on the data you plan to add to the spreadsheet. If all the data is intended for the same row, you can merge the API responses and then update that row.
However, if the data needs to be distributed across multiple rows, you will have to call the Google Sheets update row node more than once.
In any case, n8n automatically handles workflows that include more than one input item with just one node.
If you have a real workflow, feel free to share it and we can explain the process in greater detail…