To join a modded Eaglercraft server:
Some projects like or Resentful Client bundle multiple mods into a single launcher: how to add mods on eaglercraft
To play on a modded Eaglercraft server, you'll need to find one that's publicly available. You can: To join a modded Eaglercraft server: Some projects
Click "Select Pack" and upload your .zip file from your computer. Move the pack to the "Selected" column and click Done. Eaglercraft Service Workers and Userscripts how to add mods on eaglercraft