Update email status from a Gravity Form

This blog post (June 10, 2021 | Keap | Lite, Pro, and Max) shows that we can now update email status from third party apps (like Gravity Forms). But is there a list of instructions somewhere on how to do it? I’ve already updated the Gravity Forms so it has the REST API V2 like the article says, but it shows some coding and I have no idea where to put that. Ideas?

For clarification: I have a contact entered that has Unengaged Marketable status. I fill out the form, and tell it to mark as marketable but the status remains Unengaged Marketable. (Had to get Help to move it to Unengaged Marketable for testing). All the fields are updating though.