Change the RSVP Confirmation Message

tribe_change_rsvp_confirmation_msg.php

/**
 * Change the RSVP Confirmation Message
 *
 * @param string $translation The translated text.
 * @param string $text        The text to translate.
 * @param string $domain      The domain slug of the translated text.
 * @param string $context     The option context string.
 *
 * @return string The translated text or the custom text.
 */
add_filter( 'gettext', 'tribe_change_rsvp_confirmation_msg', 20, 3 );
function tribe_change_rsvp_confirmation_msg( $translation, $text, $domain, $context = "" ) {

	if (
		$domain != "default" &&
	     (
		     strpos( $domain, 'event-' ) !== 0
	     )
	) {
		return $translation;
	}

	$ticket_rsvp_text = array(
		// RSVP Confirmation Message
		'Your %1$s has been received! Check your email for your %1$s confirmation.'      => 'Custom Message',
	);

	// If we don't have replacement text, bail.
	if ( empty( $ticket_rsvp_text[ $text ] ) ) {
		return $translation;
	}

	return $ticket_rsvp_text[ $text ];
}