A chain of conversions JS code isn't working

Question

I'm learning JS and the task that comes with solution says we can create a chain like this:

let b = Boolean( BigInt(Number("1234")));
console.log('${b} [${typeof b}]');

// or

let s = "1234";
let n = Number(s);
let bi = BigInt(n);
let b = Boolean(bi);
console.log('${b} [${typeof b}]');

Output should come with a "True Boolean" but both learning platform and Chrome console says:

${b} [${typeof b}]

Am i wrong about this code? I don't know also what is the point of [] surroundings in second interpolation on both notations. Thank you for you reading this.