How to find most occuring character in JavaScript

2fmdui8.js

function maxChar(myStr) {
  let charObj = {};
  return [...myStr].reduce((_, char) => {
    if (char in charObj) charObj[char]++;
    else if (char !== " ") charObj[char] = 1;
    return Object.keys(charObj).reduce((a, b) => {
      return charObj[a] > charObj[b] ? a : b;
    });
  });
}

console.log(maxChar("The most reocurring character is r")) // --> "r"