JSFiddle - React, Tailwind, and code Playground
HTML
<div class="callout"></div>
<div class="callout" style="width:300px"></div>
<div class="callout" style="width:400px"></div>
CSS
.callout {
height: 100px;
width: 200px;
margin: 50px;
background-color: #660077;
box-shadow:0 0 0 50px #660077;
clip-path:polygon(0 0,100% 0,100% 100%,calc(100% - 10px) 100%,calc(100% - 25px) calc(100% + 30px),calc(100% - 40px) 100%,0 100%);
}