svelte/documentation/tutorial/16-special-elements/04-svelte-window/text.md

title
<svelte:window>

Just as you can add event listeners to any DOM element, you can add event listeners to the window object with <svelte:window>.

On line 11, add the keydown listener:

<svelte:window on:keydown={handleKeydown} />

As with DOM elements, you can add event modifiers like preventDefault.