It sounds like you're looking for a piece of content—likely a script, mod, or configuration snippet—for the (often typed as "120 client").
emerged not as a single official release, but as a series of community-led "re-ports" and custom clients designed to mimic or bridge the gap to the 1.20 version of the game. Key Features of the 1.20 Clients Modern Eaglercraft 1.20 clients, such as those found on repositories like Purityyy1's Eaglercraft-Java-1.20 eaglercraft 120 client
Since the game is running inside a browser’s memory, performance can vary. To get the most FPS: "Eaglercraft 1