Azure data factory calling restapi hosted on app service

Question

I am calling restapi POST method hosted on app service from azure data factory(web activity) using VNet integration runtime, I am using authentication type as NONE. but it is giving error as Error "403 Forbidden 'the web app you have attempted to reach has block your access". However linked service connection is successful for restapi url. App service hosting Rest api is integrated with vnet (private end point enabled and disabled public network) and all required nsg are there. I also tried to add managed private end point from adf to app service but it does not have any option for app service. However I am able to call same restapi successfully from postman. Please advise what could be the issue, is it possible to call restapi hosted on app service from adf?