Learn more about this change here.
For help regarding Aternos, we recommend you to visit our support center.
Our plugin browser relies on official plattforms like https://dev.bukkit.org or https://spigotmc.org and their respective APIs. Unfortunately, there are so so many sites which provide mods that this would be a mess to implement. Additionally, all of these pages don't offer an API to access the data of these sites.
Forge is not the problem, the mods are the problem.
And uploading own mods/mod pack won't be added in near future because of known reasons.
