Basic question on installation

I installed Nextcloud finally after trying unsuccessfully for a while now on Truenas Scale. I followed loosely a tutorial I saw on Youtube. In the whole process there is a step where i install a app called traefik, I had to change the normal ports i use to access Truenas 80, 443, and make it point to traefik. What is the purpose of this app?

You have installed a reversy proxy like promised, not nextcloud.

And traefik is an app handling that :wink:

You are installing apps you don’t understand?