How to install mods on your server? You may come to this page to find out the information about that. You are lucky have come to this page as here we are going to discuss about that. So, you do not go anywhere, just keep staying on this page.
STEP 1: INSTALL FORGE ON YOUR SERVER
Firstly, you need to install Forge on your server. You have to know that Forge is the server software which is necessary to load mods on your server. Forge on Aternos: https://aternos.org/software/forge/. There is an alternative to Forge, It is Magma which is based on Forge and PaperMC. It supports the installation of mods and plugins together on the same server: https://aternos.org/software/magma/.
STEP 2: INSTALL MODS ON YOUR SERVER
Now, you are able to install mods on your server. As we know that Aternos has a list with many different mods from CurseForge. Currently, only mods listed on CurseForge is able to be installed on Aternos. All mods: https://aternos.org/addons/. An example mod, DecoCraft: https://aternos.org/addons/a/curseforge/decocraft2.
STEP 3: INSTALL DEPENDENCIES ON YOUR SERVER
In this step, you will need to install dependencies on your server. Usually, several mods need other mods to work. Those are called dependencies. If it is possible the dependencies are listed on the Aternos mod list, but sometimes you need to take a look at the mod descriptions to find all dependencies. The example mod, DecoCraft, needs the installation of PTRLib to run.
STEP 4: INSTALL FORGE ON YOUR COMPUTER
Please install Forge on your computer. Most mods must be installed on both, the server and the computer of every player. To install Forge on your computer, you are able to download the installer here: https://files.minecraftforge.net/. If you use Magma on the server, so you still use Forge on the client.
STEP 5: INSTALL MODS ON YOUR COMPUTER
You have to download all the mods which you have already installed on your server and put them into your mods folder, exactly inside the minecraft folder. To download the mods, directly you are able to head to the mod pages linked in the Aternos mod list, for example: DecoCraft: https://minecraft.curseforge.com/projects/decocraft2.
STEP 6: START FORGE ON YOUR COMPUTER
Now, you are able to start your Minecraft launcher and then select the Forge profile. That was automatically made by the Forge installer (Step 4).
STEP 7: START FORGE ON YOUR SERVER
The next step that you have to do is to start your server here: https://aternos.org/server/
STEP 8: CONNECT TO YOUR SERVER
After that, you are able to connect to your server. If you have issues connecting to your server, you are able to read our article about that to get a solution. If you want a mod to be added to the mod list, so you are able to request it on the forums (https://board.aternos.org/). Before you request anything, you have to read this article: https://board.aternos.org/index.php?thread/7366-how-to-write-a-good-plugin-modpack mod-request/.
Well, the text above is an explanation about Aternos Mod Server and how to install it. Hope this benefit for you.