JSFiddle - React, Tailwind, and code Playground

HTML

<input class="form-control" data-container="body" data-content="Enter at least three characters." data-placement="top" data-toggle="popover" id="id_nickname" name="nickname" placeholder="Enter nickname here" type="text" data-original-title="" title="">
    
<button id="test-popover" type="button" class="btn btn-default">Click!</button>

JavaScript

$("#test-popover").on('click', function(){
        var anonymous_nickname = $("#id_nickname").val();
        if (anonymous_nickname.length <= 2) {
            alert('show');
        }else{
            alert('hide');
        }
    });