Nginx configuration

We have a server with an application (Qlik Sense), this app use port 80 for normal traffic but it need to use 4248 or 4244 ports to authenticate the users in the app. The problem is that the firewall where our customers will be using the application block this port and we can only use port 80. We already wrote an NGINX configuration, but it is not working, it shows the authentication dialog but after authentication we are not redirected to the application and the session is never established, we are not sure if the authentication information is not sent to sense or if the proxy is not doing the redirection correctly. Config content: events { worker_connections 1024; } http { include [login to view URL]; default_type application/octet-stream; sendfile on; keepalive_timeout 65; gzip on; map $http_upgrade $connection_upgrade { default upgrade; '' close; } server { listen 80; server_name server; location / { proxy_pass [login to view URL]; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Host $host; proxy_set_header Connection "upgrade"; proxy_redirect $scheme://$host:4248/form/ $scheme://$http_host/form/; proxy_redirect $scheme://$host:4248/windows_authentication/ $scheme://$http_host/windows_authentication/; proxy_read_timeout 60m; } location /form/ { proxy_pass [login to view URL]; proxy_http_version 1.1; proxy_set_header Host $http_host; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; proxy_read_timeout 60m; } location /windows_authentication/ { proxy_pass [login to view URL]; proxy_http_version 1.1; proxy_set_header Host $http_host; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; proxy_read_timeout 60m; } } }