URL    = "https://b24-ar17wx.bitrix24.by/rest/1/1o2...";
    ChatID = "chat" + "578";

    Result = OPI_Bitrix24.GetDialog(URL, ChatID);

    URL    = "b24-ar17wx.bitrix24.by";
    Token  = "6476c766006e9f06006b12e400000001000...";
    UserID = 10;

    Result = OPI_Bitrix24.GetDialog(URL, UserID, Token);