ngrok.yml

# Create 3 tunnels, each for different ports, with only https enabled
# This way the ngrok process stays bellow the Free plan limit (4 tunnels)

authtoken: ...
log: ngrok.log
tunnels:
  first:
    addr: 3000
    proto: http
    bind_tls: true
  second:
    addr: 8000
    proto: http
    bind_tls: true
  third:
    addr: 9999
    proto: http
    bind_tls: true

If I have t his active, how can anyone connect to my ngrok server, the hostname seem not showing and port to connect to.

For me this just assigns the same url for all (free version):

Forwarding                    https://same-url-for-all.ngrok-free.dev -> http://localhost:1234                                                                                
Forwarding                    https://same-url-for-all.ngrok-free.dev -> http://localhost:4000                                                                                
Forwarding                    https://same-url-for-all.ngrok-free.dev -> http://localhost:3000  

And it basically becomes a load balancer.