Many Eaglercraft servers use "ViaVersion" or similar plugins. This allows you to join a server using an older Eaglercraft client while the server itself runs on 1.20.1. While you might not see every single 1.20 block texture locally, you can interact with the 1.20 world and community. 2. Community Decompilations and Betas
Disclaimer: Eaglercraft is not affiliated with Mojang or Microsoft. Version - Eaglercraft eaglercraft 120 1
Pro tip: If the file opens as text, right-click it, select "Open with," and choose your browser. Many Eaglercraft servers use "ViaVersion" or similar plugins