Toogle active class using getElementById

I am trying to change class from none to active using document.getElementById but it is just adding active not removing it.

page.html

function toggleIt() {
  let collapseModel = document.getElementById(`collap_id`).className += "content active";
  collapseModel[0].classList.toggle("active")
}
.content {
  padding: 10px 20px;
  display: none;
  overflow: hidden;
  background-color: #f1f1f1;
}

.content.active {
  padding: 10px 20px;
  display: block;
  overflow: hidden;
  background-color: #f1f1f1;
}
<button onclick="toggleIt();">Open</button>

<div class="content" id="collap_id">
  Here will be all the details
</div>

When I click on toggle it then it is opening but not closing , it is also showing "Uncaught TypeError: Cannot read properties of undefined (reading 'toggle')"

I have tried many times but it is not toggling.