Inspired by this idea, I created an issue on nostr:npub1cm3rpgj7457yjuqnvdalxaauakqu0ndkpkyp5cldkyutpz4xszpsmk96wt github repository asking for a feature to be able to send Bitcoins on Spark directly to Nostr npubs.
https://github.com/BlitzWallet/BlitzWallet/issues/971