Ruby on Rails event invitation add to calendar using icalendar gem

require 'icalendar/tzinfo'class EventMailer < ApplicationMailer def send_invitation(_user, _event)  # initialize a new icalendar class  ical = Icalendar::Calendar.new  # Define default time  time_zone = 'UTC'  cal_tz = TZInfo::Timezone.get time_zone  # add timezone to icalendar   ical.add_timezone cal_tz  # new icalendar event   event = Icalendar::Event.new  # event start date  event.dtstart = Icalendar::Values::DateTime.new _event.start_time, 'tzid' => cal_tz  # event end date  event.dtend = Icalendar::Values::DateTime.new _event.end_time, 'tzid' => cal_tz  # event organizer  event.organizer = Icalendar::Values::CalAddress.new("mailto:" + _user.email)  # event created date  event.created = DateTime.now  # event location  event.location =  _event.venue  # if there's an external link e.g, google meet  event.uid = event.url = _event.meeting_link  # event title  event.summary = _event.title  # event description  event.description = _event.description  # attach the configured event to icalendar class  ical.add_event(event)  # protocol  ical.append_custom_property("METHOD", "REQUEST")  # this add's an attachment name `event.ics`,   # when clicked, the event gets added to the calendar.   mail.attachments['event.ics'] = { mime_type: 'application/ics', content: ical.to_ical }  # send mail  mail(to: _user.email, subject:  "#{_event.title} - #{_event.summary} ") endend