How to solve Uncaught TypeError: Cannot read properties of undefined (reading 'toggle')

Question

I would like to add a "-js-expanded" class to this element if someone hover over a tag. how can I do this?

<a href="" target="_self" class="sticky-cta" onmouseover="myFunction()" >
  <span class="sticky-label">GET STARTED</span>
  <i class="icon-features-productivity"></i>
</a>

  function myFunction () {
      this.classList.toggle("-js-expanded");
  }

  .-js-expanded {
  color: red;
  }

Answer 1

 function myFunction (element) { element.classList.toggle("-js-expanded"); }

 .-js-expanded { color: red; }

 <a href="" target="_self" class="sticky-cta" onmouseover="myFunction(this)" > <span class="sticky-label">GET STARTED</span> <i class="icon-features-productivity"></i> </a>