My script does not work on Sololearn Editor

Question

This script does not work on the Sololearn! meanwhile, it works well on my editor!
Could you guys please tell me how to make the script works without showing "Null"!

function calcDays(age){
"use strict"
var year = 365;
return age * year;
}

var dAge = prompt("Insert your age");

document.getElementById("test").innerHTML = calcDays(dAge);

Answer 1

Here's the solution:

https://code.sololearn.com/WFhofeEI3U3h/?ref=app