Why my Code with => doesn't work?

Question

I'm trying using => from ES6, but I just cant understand what's wrong here...can someone help me? (Also, can I write the instructions in the {...} of the function as long as I wish? Using "return" too)
https://code.sololearn.com/We8lW3RM29dG/?ref=app

Answer 1

You wanna do smthn like this?
https://code.sololearn.com/W664Q14AGrzN/?ref=app

Answer 2

Kinda, I don't need to console.log it. I just need the values of the array to become greater by 2