JSFiddle - React, Tailwind, and code Playground
HTML
<canvas id="canvas1" width="500" height="500"></canvas>
JavaScript
var can = document.getElementById('canvas1');
var context = can.getContext('2d');
var text = "test"
context.fillStyle = "red";
context.beginPath();
var radius = 100; // for example
context.arc(200, 200, radius, 0, Math.PI * 2);
context.closePath();
context.fill();
context.fillStyle = "black"; // font color to write the text with
var font = "bold " + radius +"px serif";
context.font = font;
context.textBaseline = "top";
context.fillText(text, 200-radius/4 ,200-radius/2);