so, i've been getting messages by people on how to make a proper eaglercraft server, and there is 3 ways

The free instant deployment

the 1.12 server hosted by your own way

A proper 1.21 or 26.1 server through hard proxying and velocity servers

The free instant deployment
Go to eagler.host and follow the steps

the 1.12 server hosted by your way
Get a server (free or not free) and install eaglercraftXServer plugin on your server, you should be able to join with ws:// and put the IP and PORT right after it (Example: ws://12.345.678.9.0:12345) And go to the end of the post to see how to get a proper wss:// thing

The advanced 1.21 server way
Its pretty complicated...
Ahh, ok, so i have a eaglercraft server, however since according to different replies you want to keep it 1.20, your gonna need a seperate server with the software called velocity. Make sure the main gameplay server is software paper, and install eaglerxserver on the velocity server, then, visit velocity.toml and set all online: properties to false, then go to the [servers] section and attach your gameplay server to the velocity.toml, then go to the plugins and find eaglerxserver, find the folder and put the port inject to the IP: port of your velocity server, then install viaversion, viabackwards, viarewind on your the velocity, then you should be able to join with ws://IP-Port of your velocity server! Your finally doneeeeeeeeeeeeee

How to get a proper join address
So, if your on eagler.host, you cant do anything about it, however if your hosting your own 1.12 server or the advanced 1.21 way, go to digitalplat and get a free subdomain, set the nameservers to a cloudflare connected domain to that subdomain provided by digitalplat, and wait for cloudflare domain verification, then in cloudflare, set the IP to your IP of the velocity server (DO NOT INCLUDE PORTS) then go to rules in cloudflare and make a origin rule, set it to hostname - Equals - the subdomain it gave you then scroll down and select custom port, set it to the port of your velocity server. YOUR ALL DONE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!