Even though this is becoming less and less of a problem, some devices or browsers may still not support WebGL 2. The following method allows you to check if it is supported and display a message to the user if it is not. Import the WebGL support detection module, and run the following before attempting to render anything.
import WebGL from 'three/addons/capabilities/WebGL.js';
if ( WebGL.isWebGL2Available() ) {
// Initiate function or other initializations here
animate();
} else {
const warning = WebGL.getWebGL2ErrorMessage();
document.getElementById( 'container' ).appendChild( warning );
}