One more thing -- when front-ends like nostr:npub1cm3rpgj7457yjuqnvdalxaauakqu0ndkpkyp5cldkyutpz4xszpsmk96wt and nostr:npub1hcwcj72tlyk7thtyc8nq763vwrq5p2avnyeyrrlwxrzuvdl7j3usj4h9rq sell their users to LightSpark, those users actually don't end up owning Bitcoin -- they own the Spark token, which Spark (via some mysterious process), custodially exchanges with Bitcoin.
Spark has its own address format, and is absolutely not inter-operable with Bitcoin.
When you use Rizful, you're dealing with Lightning Network primitives -- invoices.
And when you use our LSP - Megalithic.Me -- you retain full custody at all times, as all we can do is open Lightning channels to your node.