URL    = "https://b24-ar17wx.bitrix24.by/rest/1/h0m...";
    TaskID = "8502";
    FileID = "45494";

    Result = OPI_Bitrix24.AttachFileToTopic(URL, TaskID, FileID);

    URL    = "b24-ar17wx.bitrix24.by";
    Token  = "1dbf0069006e9f06006b12e400000001000...";
    TaskID = "8504";

    Result = OPI_Bitrix24.AttachFileToTopic(URL, TaskID, FileID, Token);