JSFiddle - React, Tailwind, and code Playground

HTML

<a class="dropdown-toggle" data-toggle="dropdown" id="alertingDashboardDropdown" href="#">
  <span>Alerts Dashboard</span>
  <span class="pulse">5</span>
</a>

CSS

.pulse {
  position: relative;
  display: inline-block;
  width: 22px; 
  height: 22px;
  line-height: 22px;
  border-radius: 100%;
  background-color: #cca92c;
  text-align: center;
  cursor: pointer; 
}

.pulse:before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%; 
  height: 100%;
  background-color: #cca92c;
  border-radius: 100%; 
  z-index: -1;
  animation: pulse 2s infinite; 
  will-change: transform;
}

.pulse:hover:before {
  animation: none;
}

 @keyframes pulse {
  0% {
    transform: scale(1);
    opacity: 1;
  }
  100% {
    transform: scale(2);
    opacity: 0;
  }
 }