https://didcomm.at/dm/1.0/message
This URI is a DIDComm v2 message type identifier (a PIURI), not a document to fetch — clients match on the string. It identifies the atcomm direct message carried in a DIDComm v2 encrypted envelope.
The body schema is the lexicon at.didcomm.dm. See
the spec for the message shape, envelope, and
raw lexicon.