I have a button that I want to grow and shrink over and over while the user is mousing over that button

function startHover(e) {
  btn.classList.add("btnPlaying")
}

function removeHover(e) {
  btn.classList.remove("btnPlaying");
}

const btn = document.querySelector('.btn')
btn.addEventListener("mouseenter", startHover);
btn.addEventListener('transitionend', removeHover);

.btn {
  margin-top: 10rem;
  padding: 20px 100px;
  background-color: rgb(255, 204, 3);
  border-radius: 10px;
  border-style: none;
  box-shadow: 0px 0px 10px black;
  color: blue;
  border: 4px solid rgb(53, 106, 188);
  transition: all 1.07s ease;
}

.btnPlaying {
  transform: scale(1.1);
}

<button class="btn">Play!</button>