let a = 6;
let b = 9;
let c = a * b;
// stops the execution
debugger;
console.log(c);

// debugger keyword
// You may not hear about the debugger keyword.
// It's a keyword that is used to stop the execution of the code.
const buggyCode = () => { debugger; console.log("hi");
};
// ...
buggyCode();
console.log("World");

//In code:
console.log(theVariable);
//Then in browser:
F12

If you want to dubug the code
use this only "dubugger();" in the javascript code where you want to debug step by step