sendInvoice(chatId, title, description, payload, providerToken, currency, prices, form = {}) {
    form.chat_id = chatId;
    form.title = title;
    form.description = description;
    form.payload = payload;
    form.provider_token = providerToken;
    form.currency = currency;
    form.prices = stringify(prices);
    form.provider_data = stringify(form.provider_data);
    if (form.suggested_tip_amounts) {
      form.suggested_tip_amounts = stringify(form.suggested_tip_amounts);
    }
    return this._request('sendInvoice', { form });
  }
Use this method to send an invoice.

@param {Number|String} chatId  Unique identifier for the target chat or username of the target channel (in the format `@channelusername`)
@param {String} title Product name, 1-32 characters
@param {String} description Product description, 1-255 characters
@param {String} payload Bot defined invoice payload, 1-128 bytes. This will not be displayed to the user, use for your internal processes.
@param {String} providerToken Payments provider token, obtained via `@BotFather`
@param {String} currency Three-letter ISO 4217 currency code
@param {Array} prices Breakdown of prices
@param {Object} [options] Additional Telegram query options
@return {Promise} On success, the sent [Message](https://core.telegram.org/bots/api#message) is returned
@see https://core.telegram.org/bots/api#sendinvoice