AppGateway use backend SSL port

Hello,
Is there any way to force AppGateway/WAF to redirect requests to HTTPS (443) port of backend pool?

I just want to do the following:
WAF(:80) --> Backend(:80)
WAF(:443) --> Backend(:443)

And I just have
WAF(:443) -->Backend(:80).

I have an application in backend that whenever it receives the request at port 80, it redirects to 443 and I have an infinite 301 loop.
WAF(:443) --> Backend(:80) --> SSLRedirect --> WAF(:443) --> Backend(:80)...