The Events Calendar: Eventbrite Tickets: Customize the iframe's height.

functions.php

<?php

/**
 * The Events Calendar: Eventbrite Tickets: Customize the iframe's height.
 *
 * Since Eventbrite Tickets version 4.4.6.
 *
 * @see  Tribe__Events__Tickets__Eventbrite__Template::the_tickets()
 *
 * @link https://gist.github.com/cliffordp/d1b96a03b12a74e0bd7676a46523dc9a
 */
function cliff_tec_ebtix_custom_iframe_height() {
	return 400; // pixel height
}
add_filter( 'tribe_events_eventbrite_iframe_height', 'cliff_tec_ebtix_custom_iframe_height' );