post
https://api.partners.sandbox.nowlvble.com/v1/simulation/autopay/
Use this endpoint to simulate Autopay in Sandbox environment for the user specified by external_id.
To simulate a failure in Autopay, provide a failure_reason.
This endpoint must run on the first of the month if it is a working day (weekday, not bank holiday), else the first working day before the 1st, otherwise endpoint will raise 400. The user must be approved, otherwise endpoint will raise 400.