svelte/documentation/tutorial/06-bindings/12-bind-this/text.md

title
This

The readonly this binding applies to every element (and component) and allows you to obtain a reference to rendered elements. For example, we can get a reference to a <canvas> element:

<canvas bind:this={canvas} width={32} height={32} />

Note that the value of canvas will be undefined until the component has mounted, so we put the logic inside the onMount lifecycle function.