JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id="mytext"></textarea>

CSS

textarea{
    height:400px;
}

JavaScript

var maxLength = 3;
$('#mytext').on('input focus keydown keyup', function() {
    var text = $(this).val();
    var lines = text.split(/(\r\n|\n|\r)/gm); 
    for (var i = 0; i < lines.length; i++) {
        if (lines[i].length > maxLength) {
            lines[i] = lines[i].substring(0, maxLength);
        }
    }
    $(this).val(lines.join(''));
});