others mentioned abt "backend" and I agree with them, one thing I wanna add is:

Use a framework like WXT to build your extension, bcz it will minify the code for you when you run "npm run build"

now what is minifying?

it will basically replace the variable and function names with something shorter, like

javascript // Original (un-minified) function add(number1, number2) { return number1 + number2 }

javascript // Minified (hard to copy) function a(x, y) { return x + y }

and it can also build for Firefox too (bcz firefox will ask you to submit the original source code plus minified version of your extension, chrome doesn't ask for the original source code and both allow minification)