put https://api.render.com/v1/services//env-vars
Replaces all environment variables for a service with the provided list of environment variables.
This endpoint updates the list of environment variables for a service to match the request body sent in. Any environment variables that are not included will be removed from the service.
Changes will not be deployed automatically. Instead you must call the deploy API to have changes pushed out to your service, irrespective of the autoDeploy option set on the service.