问按钮在计数器达到阈值后变得可见。

EN

var money = 0
const addMoneyButton = document.getElementById('Clicker')

const addMoney = () => {
  money += 1
  document.getElementById("money").innerHTML = money
  console.log(money)

  function upgrade1() {
    var upgrade1 = document.getElementById('upgrade1')
    if (money > 10) {
      upgrade1.style.visibility = 'visible'
    }
  }
  // here!
  upgrade1()
}

addMoneyButton.addEventListener("click", addMoney)

<button id="Clicker">Click To Begin Making Money</button>
<br>
<button id='upgrade1' style="visibility:hidden;">Upgrade Money Amount</button>
<h1>Money Amount: <span id='money'></span></h1>

const clicker = document.getElementById('Clicker');
const upgrade1 = document.getElementById('upgrade1');
const money = document.getElementById('money');

let count = 0;
clicker.addEventListener('click', () => {
  money.textContent = ++count;
  if (count > 10) upgrade1.style.visibility = 'visible';
});

<button id="Clicker">Click To Begin Making Money</button>
<button id='upgrade1' style="visibility:hidden;">Upgrade Money Amount</button>
<h1>Money Amount: <span id='money'></span></h1>