The following CID refers to a blank file on the IPFS network:
bafkreihdwdcefgh4dqkjv67uzcmw7ojee6xedzdetojuzjevtenxquvyku
Try it:
https://cloudflare-ipfs.com/ipfs/bafkreihdwdcefgh4dqkjv67uzcmw7ojee6xedzdetojuzjevtenxquvyku
Code
I generated the CID using the following code:
import { createHelia } from 'helia'
import { unixfs } from '@helia/unixfs'
const helia = await createHelia({ start: false })
const fs = unixfs(helia)
const cid = await fs.addBytes(Buffer.from([]))
console.log(cid)