ECP > Add the virtual event URL to the end of the description in the iCal exports.

functions.php

<?php
/**
 * Insert virtual event meeting URL at the end of the description.
 *
 * @param array $item   Array of items describing the event in ical format.
 * @param object $event The event object.
 *
 * @return array
 */
add_filter( 'tribe_ical_feed_item', function ( $item, $event ) {
	if ( isset( $event->virtual_meeting_url ) ) {
		$item['DESCRIPTION'] .= '\n\nClick on this link to join the meeting:\n' . $event->virtual_meeting_url;
	}

	return $item;
}, 10, 2 );