"Error in connection establishment" when nginx points to another server

[ResetButton]

Hello!
I'm stuck in situation how to pass websockets requests in situation when I've 2 servers in chain.
Here is it

1. A domain name (domain.dev), with A record
2. intranet server Add Debug Dashboard #1, which has external IP and nginx with SSL installed that proxifying requests from external IP to internal, depending on domain name
3. intranet server Websockets route #2, which contains service with websocket on standart port, this server has no direct access to internet

So sheme is
Domain.dev (A record points to Server #1 ) => Server #1 (with nginx and SSL for domain.dev) => Server #2 (with websocket server on standart port 6001)

I tried lots of variants and always get errors like

WebSocket connection to 'wss://******' failed: Error in connection establishment: net::ERR_CONNECTION_REFUSED
WebSocket connection to 'wss://********' failed: WebSocket is closed before the connection is established.

As I mentioned problem is that my service is configured for accepting http connections, but connections is sending via https (wss:).
I read official manual https://docs.beyondco.de/laravel-websockets/1.0/basic-usage/ssl.html#usage-with-a-reverse-proxy-like-nginx but can't understand how handle same 'location' for http and websockets requests
So this config part from example

location / {
    proxy_pass             http://127.0.0.1:6001;

is for websockets only? But how I can forward normal requests?

My Configs
app.js

 window.Echo = new Echo({
     broadcaster: 'pusher',
     key: process.env.MIX_PUSHER_APP_KEY,
     cluster: process.env.MIX_PUSHER_APP_CLUSTER,
     wsHost: window.location.hostname,
     disableStats: true,
     wsPort: 6001,
     wssPort: 6001 //HTTPS only
 });

broadcasting.php

 'options' => [
                'cluster' => env('PUSHER_APP_CLUSTER'),
                'host' => '127.0.0.1',
                'port' => 6001,
                'encrypted' => false, //# for HTTP
                'scheme' => 'http', //# for HTTP
                //'scheme' => 'https', //#for HTTPS
                'curl_options' => [
                    CURLOPT_SSL_VERIFYHOST => 0,
                    CURLOPT_SSL_VERIFYPEER => 0,
                ]
            ],

websockets.php

[
            'id' => env('PUSHER_APP_ID'),
            'name' => env('APP_NAME'),
            'key' => env('PUSHER_APP_KEY'),
            'secret' => env('PUSHER_APP_SECRET'),
            'path' => env('PUSHER_APP_PATH'),
            'capacity' => null,
            'enable_client_messages' => true,
            'enable_statistics' => false,
        ],

nginx config is total trash now :) so please point me to right direction.

[33sKamal]

same problem

[llioorkd]

Solved!
nginx.conf:

# API
server {

    listen 80;
    listen [::]:80;

    server_name example.com;
    root /home/ubuntu/www/public;
    index index.php index.html index.htm;

    location / {
         try_files $uri $uri/ /index.php$is_args$args;
    }

    location /app {
            proxy_pass             http://127.0.0.1:6001;
            proxy_read_timeout     60;
            proxy_connect_timeout  60;
            proxy_redirect         off;

            # Allow the use of websockets
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection 'upgrade';
            proxy_set_header Host $host;
            proxy_cache_bypass $http_upgrade;
    }