A 501 error indicates a call to an unsupported back-end function. This sample response shows a typical 501 error:
{
"detail": "Functionality not supported.",
"errorCode": "EW4701",
"instance": "/edgeworkers/error-instances/76b1595d-08e5-46a8-8bc6-72d01e621303",
"status": 501,
"title": "Not implemented.",
"type": "/edgeworkers/error-types/edgeworkers-not-implemented"
}