// SendMsgReq extends SendMsg with the requirement of RecvID when SessionType indicates a one-on-one or notification chat.
typeSendMsgReqstruct{
// RecvID uniquely identifies the receiver and is required for one-on-one or notification chat types.
RecvIDstring`json:"recvID" binding:"required_if" message:"recvID is required if sessionType is SingleChatType or NotificationChatType"`
RecvIDstring`json:"recvID" binding:"required_if" message:"recvID is required if sessionType is SingleChatType or NotificationChatType" binding:"required"`