step 1: download modrinth app !! modrinth basically hold the mods so you dont have to download and install them yourself
download: https://modrinth.com/app
step 2: download the mod file and create and instance by clicking the plus button on the side and then choosing from file option
download: Download mod file 1.0.0.mrpack | LimeWire ( I KNOW THE SITE LOOKS SKETCHY I PROMISE IT'S FINE )
step 3: press play on the instance and then make enter the ip and everything like usual !!
btw !! the server has to be turned on to use it because thats just how aternos servers work so i would recommend creating an account so i can just give you perms to turn it on whenever you want !!