prove_transaction

// Pre-build proving key (optional, for better UX)
if (!t2z.is_proving_key_ready()) {
  t2z.prebuild_proving_key();
}

// Generate proofs
const provedPczt = t2z.prove_transaction(pczt);

// Verify proofs were added
const info = t2z.inspect_pczt(provedPczt.to_hex());
console.log('Has proofs:', info.has_orchard_proofs);