Reverse Proxy CouchbaseLite Exception

This is following a very specific request, I have to go through a reverse proxy so that one of my users can use my application. To give you a quick summary, only ports 80 and 443 have been authorized for him. Therefore, it is not possible to go through port 4984 to communicate with SYNC GATEWAY.
So I had the idea to set up a reverse proxy so that it could still use my application.

Namely that my server is on Windows Server 2016 so I use IIS.
I have created my two rules (incoming and outgoing) and my network administrator tells me that everything is fine on this side. To tell you when I type in my web browser: [URL_SERVER]: 80 / {NAME_BUCKET}, I arrive of course on the popup which asks me for the name and the password. And I can see the little text that tells me that I am well connected.
On the other hand, as soon as I try to connect via my application by putting [URL_SERVEUR]: 80 / {NAME_BUCKET] I have a small error message:
"CouchbaseLiteException (WebSocketDomain / 1002): Invalid ‘Connection’ header.

Could someone help me on this subject, because I’m starting to run out of ideas …

It looks like your proxy doesn’t understand websockets and is stripping needed headers out of it.

As you can see I am just using the reverse proxy feature of IIS.
Is it possible to use a reverse proxy to manage SyncGateway requests?