JSFiddle - React, Tailwind, and code Playground

HTML

<p></p>

CSS

body {
    background: #ff004e;
    padding:40px;
}
p {
    background:white;
    border-radius: 10px;
    width:250px;
    height:150px;
    position: relative;
    display: inline-block;
}
p:before {
    content:"";
    position: absolute;
    height: 45px;
    width: 16px; /* 1px buffer for zooming problems while rendering*/
    top: 50px;
    left: -15px; 
    background: white;
}
p:after {
    content:"";
    position: absolute;
    height: 40px;
    width: 15px;
    border-radius: 0 40px 40px 0;
    top: 75px;
    left: -15px;
    background: #ff004e;
    box-shadow: 0 -45px 0 0 #ff004e;
}