Layer 4 apt for ssh tunnel

1. The problem I’m having:

Hi, I am using Caddy as file server on example.com and as reverse proxy on several subdomains. Now I want to utilize my ssh tunnel to get to a machine behind a nat (rpi). I run

 autossh -M 0 -f -o ConnectTimeout=10 -o ServerAliveInterval=60 -o ServerAliveCountMax=2 -i /home/user/.ssh/key -N -R 8080:rpi:22 rnglr.be

In the nat I can ssh to rpi on the standard port.
With caddy running on example.com I need to run the layer 4 app:

{
  "apps": {
    "layer4": {
      "servers": {
        "example": {
          "listen": [
            "0.0.0.0:8000"
          ],
          "routes": [
            {
              "match": [
                {
                  "ssh": []
                }
              ],
              "handle": [
                {
                  "handler": "proxy",
                  "upstreams": [
                    {
                      "dial": [
                        "localhost:8080"
                      ]
                    }
                  ]
                }
              ]
            }
          ]
        }
      }
    }
  }
}

So now I want to

ssh -p 8000 example.com

to get to rpi on port 22. But it does not work:

 ssh -p 8000 example.com
ssh: connect to host example.com port 8000: Connection refused

Do I have to install the app somehow? I just loaded the Caddyfile I used and converted it to json and added the layer4 part shown above.

2. Error messages and/or full log output:

no entries

3. Caddy version:

h1:q3pe0wpBj1OcHFZ3n/1nl4V4bxBrYoSoab7rL9BMYNk=

4. How I installed and ran Caddy:

official packages

a. System environment:

Linux ubuntu 6.8.0-49-generic #49-Ubuntu SMP PREEMPT_DYNAMIC x86_64 x86_64 x86_64 GNU/Linux

Ok, I found that I have to install and how to install the layer4 app: Build from source — Caddy Documentation.

Is there a way to get the custom build from Download Caddy via wget onto my machine?

==

Edit: I managed to install:

wget https://caddyserver.com/api/download?os=linux&arch=amd64&p=github.com%2Fmholt%2Fcaddy-l4&idempotency=35420498813403

I still get a connection refused.