JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id="text"></textarea>
    <p id="text2"></p>
    <button onclick="multi_line_textarea()">on textarea</button>
    <button onclick="multi_line_para()">on paragraph</button>

    <script>
        function multi_line_textarea(){
            var text = "line 1. \nline 2. \nline 3.";
            var el = document.getElementById('text');
            el.innerHTML = text;
        }
        function multi_line_para(){
            var text2 = "line 1. <br/>line 2. <br/>line 3.";
            var el2 = document.getElementById('text2');
            el2.innerHTML = text2;
        }
    </script>