How do I convert $context.requestTime or $context.requestTimeEpoch to UTC in a body mapping template? In AWS App sync this can be done with https://docs.aws.amazon.com/appsync/latest/devguide/time-helpers-in-util-time.html.

I did find this answer but that was two years ago surly there is a shorter way.

This logic can be performed it VTL templates but there is not a one-to-one function call in APIGW templates to VTL templates