What question mark functionality in js

Question

What does this question mark do in this specific code bellow
https://code.sololearn.com/Wt4qxO8FCoFw/?ref=app

Answer 1

https://stackoverflow.com/questions/63806017/what-does-the-question-mark-mean-in-the-return-statement-in-js
//
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining

Answer 2

Let's google it!
https://javascript.plainenglish.io/what-does-the-question-mark-mean-in-javascript-code-353cfadcf760
https://www.sololearn.com/Discuss/1903556/what-does-the-question-mark-mean-in-js
https://www.freecodecamp.org/news/how-the-question-mark-works-in-javascript/amp/

Answer 3

It's not the question mark i mean

Answer 4

Yeah that is what i mean