Steve on Nostr: Has anyone gotten LNMarkets LNURL callbacks to work? I've manually done my own LNURL ...

Has anyone gotten LNMarkets (npub1lnm…tnnn) LNURL callbacks to work? I've manually done my own LNURL auth, but their callback asks for an HMAC.

I thought you only needed the k1 (provided by me), signature and publickey (provided by wallet) to confirm a signature?

(it also wants an HMAC and tag)

https://docs.lnmarkets.com/api/operations/lnurlvalidateauth