Good morning everyone. I am trying to install Koha on a server with Ubuntu, following the steps indicated on the following website:

https://wiki.koha-community.org/wiki/Koha_on_Debian#Create_a_Koha_instance

The problem comes when I try to access the self-installer's website via the web.

The Apache server is accessible (www.alejandria.dadoscolgados.com) but I am not able to enter the system, since the "internal" part cannot find it. That is, I can't reach "libraryname.host".

The installation is based on addresses and not only on IP

I have control over the DNS domain and everything, so I could make any modifications.

Could you give me a hand?