resolve
Resolve an offer URI and report whether it requires a transaction code.
Call this before acceptOffer so the UI knows whether to prompt the user for a code (and what kind of keyboard / length to show). A null result means the offer is an authorization-code offer that needs no code — call acceptOffer with txCode = null.
Return
The OfferTxCodeSpec for pre-authorized offers, or null.
Parameters
uri
The credential offer URI.
Throws
if the offer cannot be resolved.