Hide ET/ET+ forms on single event pages if JavaScript is disabled. Useful when Attendee Meta fields are used. WITH THIS SNIPPET, when JavaScript is disabled: https://cl.ly/1N452v3T3O17

functions.php

<?php

/*
 * from https://gist.github.com/cliffordp/9edebb79954507935ddb8a9b323ae1b5
 * 
 * The Events Calendar and Event Tickets / Event Tickets Plus
 * Hide ET/ET+ forms on single event pages if JavaScript is disabled
 * And display text informing the user in a <noscript> tag
 * Useful when Attendee Meta fields are used -- currently do not get displayed (even Required fields) unless browser has JavaScript enabled (ref: https://central.tri.be/issues/63912)
 * 
 * Without this snippet:
 * With JavaScript enabled: https://cl.ly/0H2M3H3g0S1f
 * With JavaScript disabled: https://cl.ly/2G3c3Y2A2p2S
 *
 * WITH THIS SNIPPET, when JavaScript is disabled: https://cl.ly/1N452v3T3O17
 *
 * @link https://www.w3.org/TR/html401/interact/scripts.html#edef-NOSCRIPT
 *
 */
add_action( 'wp_head', 'cliff_et_if_js_disabled_hide_tickets' );
function cliff_et_if_js_disabled_hide_tickets() {
	// cannot do
	// remove_action( 'tribe_events_single_event_after_the_meta', array( 'Tribe__Tickets__Tickets', 'front_end_tickets_form' ), 5 );
	// because we do not know if JavaScript is enabled at the point that would run... so we have to hide via CSS, at least for this hack
	
	$id = get_the_ID();
	
	if ( ! function_exists( 'tribe_is_event' ) || ! tribe_is_event( $id ) ) {
		return false;
	}
	
	// tribe_events_has_soldout() also TRUE if event has no tickets whatsoever
	if ( ! function_exists( 'tribe_events_has_soldout' ) || tribe_events_has_soldout( $id ) ) {
		return false;
	}
			
	echo '<style type="text/css">
	body.tribe-no-js #buy-tickets ~ form {
		display: none !important;
	}
	body.tribe-no-js #event-tickets-noscript {
		margin: 20px auto;
		border: 4px solid red;
		padding: 20px;
	}
	body.tribe-no-js #event-tickets-noscript p:last-child {
		margin-bottom: 0;
	}
	</style>';
	
	add_action( 'tribe_events_single_event_after_the_meta', 'cliff_et_if_js_disabled_add_noscript_text' );
}

// @link https://developer.wordpress.org/reference/functions/esc_html/
function cliff_et_if_js_disabled_add_noscript_text() {
	printf( '<div id="event-tickets-noscript"><noscript>%1$s
		<p>%2$s</p>
		<p>%3$s <a href="http://enable-javascript.com/" target="_blank"><strong>enabling JavaScript</strong></a> (link opens in a new window)</p>
		<p>%4$s</p>
		</noscript></div>%1$s',
		PHP_EOL, // 1
		esc_html( 'Tickets are available for this event, but you must enable JavaScript in order to order them! :(' ), // 2
		esc_html( 'Please come back to this page after'), // 3
		esc_html( 'Thank you.' ) // 4
	);
}