Workaround for JSON error on Sage theme with AR Page

functions.php

<?php

/**
 * This is a workaround to make AR page work with Sage theme JSON errors.
 * 
 * Under Tickets > Settings > Attendee Registration
 * -> Set Attendee Registration Slug to 'attendee-registration'
 * -> Don't choose any page.
 * -> Now create a Page with the shortcode [tribe_attendee_registration] and use the slug `attendee-registration-info` for that page.
 * -> Then just copy and paste this code in your theme's functions.php file.
 */
add_filter( 'woocommerce_get_checkout_url', 'rt_et_force_page_slug_manually', 60 );
function rt_et_force_page_slug_manually( string $url ) {

	// if url has tickets-provider in it, then we need to force the page slug
	if ( strpos( $url, 'tickets_provider' ) !== false ) {
		$force_page_slug = 'attendee-registration-info';
		// replace slug from url
		$url = str_replace( 'attendee-registration', $force_page_slug, $url );
	}

	return $url;
}