You cannot change the 8008 port, it has to be 8008 externally (i.e. from the client side).
You can however do subdomain, but only these will work:
api.mydomain.com app.mydomain.com files.mydomain.com

CooperativeSealion8

when it first asks me to enter my full name

Where? in the Web?

I might have missed it

Alright. Thank you

ubuntu 18.04

We should probably make sure it is properly stated in the documentation...

The error i see in the server logs

will the client know to use these subdomains automatically?

using docker-compose

Seems like something is not working with the server, i.e. it cannot connect with one of the dockers.
May I suggest to carefully go through all the steps here, make sure nothing was missed
https://github.com/allegroai/trains-server/blob/master/docs/install_linux_mac.md

Especially number (4)

Yes, as long as the client is served from http://app.something.com it will look for the api server at http://api.something.com

What's the OS running the server?

yes

obviously http://app.trains.domain.com will also work

CooperativeSealion8 let me know if you managed to solve the issue, also feel free to send the entire trains-server log. I'm assuming one of the dockers failed to boot...

Oh got it. Thank you so much!

I am using NGINX to route to docker so I routed only the 8080 port and forgot about the 8008 port which caused the error. I’m trying to figure out now how to route both ports simultaneously