New feature: PUT support
By @ana
In general, GET is for getting data into your sheet (makes sense). POST is for creating new records, and PUT is for updating data that already exists. There are already some interesting use cases for this; one of API Connector's users messaged me to say he adds a list of leads into Google Sheets, uses another add-on to send each one a slightly personalized mass email, and then uses API Connector to automatically run down the list and PUT all their contact status to "email sent".
Documentation: https://mixedanalytics.com/knowledge-base/add-body-post-requests/