default rsvp attendees to be opted in to being displayed in attendees list

example.php

<?php
/**
 * Block: RSVP
 * Actions - Success - Toggle
 *
 * Override this template in your own theme by creating a file at:
 * [your-theme]/tribe/tickets/v2/rsvp/actions/success/toggle.php
 *
 * See more documentation about our Blocks Editor templating system.
 *
 * @link https://evnt.is/1amp Help article for RSVP & Ticket template files.
 *
 * @var Tribe__Tickets__Ticket_Object $rsvp                 The rsvp ticket object.
 * @var boolean                       $opt_in_toggle_hidden The order status of the RSVP that was made.
 * @var string                        $opt_in_attendee_ids  The list of attendee IDs to send.
 * @var string                        $opt_in_nonce         The nonce for opt-in AJAX requests.
 * @var boolean                       $opt_in_checked       Whether the opt-in field should be checked.
 *
 * @since 5.0.0
 * @version 5.0.0
 */

if ( $opt_in_toggle_hidden ) {
	return;
}

$toggle_id = 'toggle-rsvp-' . $rsvp->ID;
?>

<div class="tribe-tickets__rsvp-actions-success-going-toggle tribe-common-form-control-toggle">
	<input
		class="tribe-common-form-control-toggle__input tribe-tickets__rsvp-actions-success-going-toggle-input"
		id="<?php echo esc_attr( $toggle_id ); ?>"
		name="toggleGroup"
		type="checkbox"
		value="toggleOne"
		checked="checked"
		style="display: none;"
		data-rsvp-id="<?php echo esc_attr( $rsvp->ID ); ?>"
		data-attendee-ids="<?php echo esc_attr( $opt_in_attendee_ids ); ?>"
		data-opt-in-nonce="<?php echo esc_attr( $opt_in_nonce ); ?>"
	/>

	<?php $this->template( 'v2/rsvp/actions/success/tooltip', [ 'rsvp' => $rsvp ] ); ?>
</div>

<script type="text/javascript">

	if ( typeof $input === 'undefined' ) {
		const $input = jQuery( '.tribe-tickets__rsvp-actions-success-going-toggle-input' );
		const $container = jQuery('.tribe-tickets__rsvp-wrapper');

		const data = {
			action: 'tribe_tickets_rsvp_handle',
			ticket_id: $input.data( 'rsvp-id' ),
			step: 'opt-in',
			opt_in: true,
			opt_in_nonce: $input.data( 'opt-in-nonce' ),
			attendee_ids: $input.data( 'attendee-ids' ),
		};

		tribe.tickets.rsvp.manager.request( data, $container );
	 }

</script>