Can't get HA add-on Ingress to work, what am I doing wrong?

I have an add-on which has a web-server on port 5052 and if in the config.yaml for the add-on I set:

ports:
5052/tcp: 5052
ports_description:
5052/tcp: Web interface

Then the web interface works fine on homeassistant.local:5052

However I want to support ingress so in the config.yaml I set:

ingress: true
ingress_port: 5052

When I re-install the add on and click on the ingress it says its unavailable. What am I missing?

Hi Trefor Southwell,

This post might help you.
How to add custom buttons to the side toolbar.

Okay, problem solved - the web interface needs to have relative links (./config) rather than absolute ones (/config)!