402cron — why am I receiving these requests?

402cron delivers scheduled HTTP requests on behalf of automated clients.

We only ever deliver to an address that ANSWERED OUR CHALLENGE. Someone with
control of that exact URL registered it and proved it. If that was not you,
the endpoint is not as private as you believe.

Every request we send carries:
  X-402cron-Delivery-Id   which execution it belongs to
  X-402cron-Task-Id       which task
  X-402cron-Signature    proof it is really from us

To stop them, do any one of these:
  - Return 4xx. We do not retry a refusal, and repeated refusals pause the task.
  - Remove or rename the endpoint.
  - Write to the address below with one Delivery-Id, and we will stop it.

Contact: abuse@402cron.com
Service: https://402cron.com/.well-known/402cron.json