URL    = "https://b24-ar17wx.bitrix24.by/rest/1/f2ppp8uucc891111/";
    ChatID = "450";

    Title = "New chat title";

    Result = OPI_Bitrix24.ChangeChatTitle(URL, ChatID, Title);

    URL    = "b24-ar17wx.bitrix24.by";
    Token  = "fe3fa966006e9f06006b12e400000001000...";
    ChatID = "452";

    Title = "Another title";

    Result = OPI_Bitrix24.ChangeChatTitle(URL, ChatID, Title, Token);