ahora funciona bien descargar desde el lado del Form

src/lib/form/Form.svelte

@@ -1,9 +1,9 @@
 <script>
 	import { onMount } from 'svelte';
-	import { title, heading, subtitle, content, date, address } from '$lib/stores/store';
+	import html2canvas from 'html2canvas';
+	import { title, heading, subtitle, content, date, address, canvas } from '$lib/stores/store';
 
 	/** @type {HTMLDivElement} */ let editor;
-	let innerHTML;
 
 	const handleSubmit = async () => {
 		console.log('submit');
@@ -17,6 +17,17 @@
 		$content = editor.firstChild.innerHTML;
 	};
 
+	const downloadCanvas = async () => {
+		if ($canvas !== undefined) {
+			const res = await html2canvas($canvas);
+			const image = await res.toDataURL('image/png');
+			const link = document.createElement('a');
+			link.download = 'cartel.png';
+			link.href = image;
+			link.click();
+		}
+	};
+
 	const quillOptions = {
 		modules: {
 			toolbar: [['bold', 'italic']]
@@ -70,6 +81,7 @@
 		</div>
 	</div>
 </form>
+<button on:click|preventDefault={downloadCanvas}>Descargar</button>
 
 <style>
 	.form-group {

src/lib/preview/Preview.svelte

@@ -1,9 +1,8 @@
 <script>
 	import html2canvas from 'html2canvas';
-	import { title, subtitle, date, address, content, heading } from '$lib/stores/store';
+	import { title, subtitle, date, address, content, heading, canvas } from '$lib/stores/store';
 
 	let newdate = '';
-	let inner;
 
 	const convertDateTime = (datetime) => {
 		if (datetime == undefined) {
@@ -25,19 +24,10 @@
 	$: if ($date !== '') {
 		newdate = convertDateTime($date);
 	}
-
-	const takeScreenshot = async () => {
-		const res = await html2canvas(inner);
-		const image = await res.toDataURL('image/png');
-		const link = document.createElement('a');
-		link.download = 'cartel.png';
-		link.href = image;
-		link.click();
-	};
 </script>
 
 <div class="preview">
-	<div class="result" bind:this={inner}>
+	<div class="result" bind:this={$canvas}>
 		<div class="heading">{$heading}</div>
 		<div class="title">{$title}</div>
 		<div class="subtitle">{$subtitle}</div>
@@ -46,7 +36,6 @@
 		{#if newdate}<div class="time">{newdate.time}</div>{/if}
 		<div class="address">{$address}</div>
 	</div>
-	<button on:click|preventDefault={takeScreenshot}>Descargar</button>
 </div>
 
 <style>

src/lib/stores/store.js

@@ -6,3 +6,4 @@ export const subtitle = writable("");
 export const content = writable("");
 export const date = writable("");
 export const address = writable("");
+export const canvas = writable();