How do I use a custom variable in my json data feed?

Use the Save API Input To Variable action to create a custom variable that can be used in your Save Structured Data output, allowing you to pull data from outside your task into your data feed.

Ensure you place the Save API Input To Variable step before your looping iteration.

Open the Variables drop-down menu and copy-paste the save_api_input_to_variable step ID into the Data Picker field to add the custom variable.