Currently, there is of a native Eaglercraft 1.16 client published by the original developers. Most community members still play on the stable Eaglercraft 1.8.8 version.
However, players can access 1.16 content through specific workarounds:
Once the server appears online, double-click to start playing. Eaglercraft
Using tools like ViaVersion and ViaBackwards , community members have successfully "translated" 1.16 server data so it can be played using an Eaglercraft 1.8.8 client.