<input type="text" id="name" onblur="Uname();" placeholder="onblur"/>

        body{
            display: flex;
            height: 100vh;
            align-items: center;
            justify-content: center;
        }
        input {
            display: block;
            color: #e53f3f;
            border: 2px solid #262626;
            border-radius: 20px;
            padding: 5px;
            padding-left: 10px;
            outline: none;
            font-family: Verdana;
            font-weight: bold;
            box-shadow: 0px 10px 20px #262626;
        }

   function Uname() {
            let name = document.getElementById("name");
            name.value = name.value.toUpperCase();
        }