val signatureType: String
a did:sov:BzCbsNYhMrjHiqZDTUASHg;spec/signature/1.0/ed25519Sha512_single
signatureType - a did:sov:BzCbsNYhMrjHiqZDTUASHg;spec/signature/1.0/ed25519Sha512_single
signatureType