For developers looking to implement rank-based features legitimately, you can learn to use —Roblox's official programming language—to create your own experiences.

If you're interested in learning how to script your own features or understanding how local scripts work within Roblox, this video provides a helpful overview: What are Local Scripts? Roblox Scripting Explained YouTube• Nov 24, 2021

Searching for or using "rank bypass" or "become any rank" scripts is generally associated with game exploiting, which carries several risks:

Are exploiters able to read local scripts? - Developer Forum | Roblox

Roblox scripts use the Luau programming language, which is derived from Lua 5.1. Roblox Creator Hub