Which internal IP does your router port forward ports 80 and 443 to?
Is that the same IP as the NAS?
[be sure your ISP is not blocking port 80]
I get this for port 80 from outside:
curl -Iki http://home.rolland.net/
curl: (7) Failed to connect to home.rolland.net port 80: No route to host
and these for port 443:
curl -Iki https://home.rolland.net/
curl: (7) Failed to connect to home.rolland.net port 443: Connection refused
curl -Iki https://home.rolland.net/
HTTP/1.1 403 Forbidden
Date: Thu, 04 Jun 2020 08:17:01 GMT
Server: Apache
Last-Modified: Tue, 26 Apr 2016 09:33:13 GMT
ETag: "1e5-5315ffb666840"
Accept-Ranges: bytes
Content-Length: 485
Vary: Accept-Encoding
Content-Type: text/html