sdk API for user bz: client req json e.g.:"{\"params\":{\"expiration\":\"2019-11-13T06:28:32.279212Z\",\"service_info\":{\"address\":\"nch1ugus2df3sydca3quula5yjqfntuq5aaxweezpt\",\"type\":1},\"user_address\":\"nch1ugus2df3sydca3quula5yjqfntuq5aaxweezpt\"},\"signature\":{\"pub_key\":\"02b2bf9a87dd7cf1ad998721ffef00713a4d5fb2bae0316eea04268ae877a0bcac\",\"signature\":\"c2b822b4ddfbce95feb44112bce0022bbce67126b9fd50447e9ce3e0d03000ac287698c4994a892834921d5c2e3fe901d13f078eb54b289286831afb8046afe0\"}}" */.