Prove you own this wallet.
For payees not yet in the directory: sign a one-time code with the wallet. This does not let a scam site impersonate a known brand — lookalikes of onboarded merchants still block. Known vendors are trusted via out-of-band onboarding, not a badge on their page.
1 · Your business and wallet
2 · What you sign
Your wallet will show a message with a one-time code like PG-482913. Signing proves you hold the wallet's private key. A scammer with a lookalike address can't produce this signature for the real wallet.