After some more hacking with #[0] I finally got Zaps to work properly with my Core Lightning node. All you need is two plugins:
* clnurl: LNURL server with Nostr support
* cln-zapper: Broadcast zap notes when invoices are paid 
GitHub
GitHub - elsirion/clnurl: Playing around with CLN and LNURL
Playing around with CLN and LNURL. Contribute to elsirion/clnurl development by creating an account on GitHub.
GitHub
GitHub - thesimplekid/cln-zapper-rs: Core Lightning plugin for sending zap (NIP-57) notes
Core Lightning plugin for sending zap (NIP-57) notes - thesimplekid/cln-zapper-rs