declineChatJoinRequest(chatId, userId, form = {}) {
    form.chat_id = chatId;
    form.user_id = userId;
    return this._request('declineChatJoinRequest', { form });
  }
Use this method to decline a chat join request.

The bot **must be an administrator in the chat** for this to work and **must have the `can_invite_users` administrator right**.

@param {Number|String} chatId Unique identifier for the target chat or username of the target channel (in the format `@channelusername`)
@param {Number} userId  Unique identifier of the target user
@param {Object} [options] Additional Telegram query options
@return {Promise} True on success
@see https://core.telegram.org/bots/api#declinechatjoinrequest