Send http post - set a number of days in expiry_date instead of a specific date


I’m using Send HTTP post in advanced automations.

At some point I had found a way to set a number of days in the expiry_date field instead of a particular date (maybe you have to use a different variable instead, can’t remember).

For example, set the post to expire in 30 days, counting from today.

I can’t find this in Keap’s documentation any more. Has anyone done it?