A simple code to upload blob on firebase storage.

firebase-blob-uplaod.svelte

<script lang="ts">
	import firebaseApp from '$lib/firebase';
	import { uploadBytes, getStorage, ref } from 'firebase/storage';

	const onChange = (event: Event) => {
		const target = event.target as HTMLInputElement;
		if (!target) return;

		if (target.files && target.files.length > 0) {
			const selectedFile = target.files[0];

			const fileBlob = new Blob([selectedFile], { type: selectedFile.type });

			const storage = getStorage(firebaseApp);
			const storageRef = ref(storage, `file/${selectedFile.name}`);

			uploadBytes(storageRef, fileBlob)
				.then((data) => console.log(data))
				.catch((err) => console.error(err));
		}
	};
</script>

<input type="file" name="file" id="file" on:change={onChange} />