async function fileSaveAs(blob) {
	try {
		// @ts-ignore
		const writable = await (await window.showSaveFilePicker({
			types: [
				{
					description: 'PNG Image',
					accept: {
						'image/png': ['.png']
					}
				}
			]
		})).createWritable();
		await writable.write(blob);
		await writable.close();
	} catch {
		alert('File not saved');
	}
}
save file with "File save as" dialog
@param {Blob} blob