Example of generated ICS

BEGIN:VCALENDAR
VERSION:2.0
PRODID:ICS.php
X-WR-CALNAME:Timetable
NAME:Timetable
CALSCALE:GREGORIAN
REFRESH-INTERVAL;VALUE=DURATION:P15M
BEGIN:VTIMEZONE
TZID:Europe/Moscow
TZURL:http://tzurl.org/zoneinfo-outlook/Europe/Moscow
X-LIC-LOCATION:Europe/Moscow
BEGIN:STANDARD
TZOFFSETFROM:+0300
TZOFFSETTO:+0300
TZNAME:MSK
DTSTART:19700101T000000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
BEGIN:VALARM
ACTION:DISPLAY
DESCRIPTION:Economics
TRIGGER:-PT2M
END:VALARM
URL:zoom.us
LOCATION:209
DESCRIPTION:Page 32, ex. 3
DTSTART;TZID=Europe/Moscow:20210410T124000
DTEND;TZID=Europe/Moscow:20210410T132000
SUMMARY:Economics
END:VEVENT
END:VCALENDAR