JSFiddle - React, Tailwind, and code Playground
HTML
<link rel="stylesheet" href="http://leafletjs.com/dist/leaflet.css">
<script src="http://leafletjs.com/dist/leaflet.js"></script>
<div id="map" style="width: 600px; height: 400px"></div>
JavaScript
var map = L.map('map').setView([51.505, -0.09], 13);
L.tileLayer('https://{s}.tiles.mapbox.com/v3/{id}/{z}/{x}/{y}.png', {
maxZoom: 18,
id: 'examples.map-i875mjb7'
}).addTo(map);
m = L.marker([51.5, -0.09]).addTo(map);
m.bindPopup("<b>Hello world!</b><br />I am a popup<span id='a'></span>", {maxWidth: "none"})
m.openPopup();
$('#a').html('abcdefghijklmnopqrstuvwxyz')