Using data from the form, insert post id, notification settings

jet-engine-use-inserted-post-id.php

<?php

$on_insert_port = function ( $settings, $notification ) {
	if ( 'post' !== $settings['post_type'] ) {
		return;
	}

	/**
	 * To get/set the entered data from the form use $notification->data
	 */
	$post_id  = (int) $notification->data['inserted_post_id'];
	$meta_key = '_is_adult';
	$is_adult = absint( $notification->data['age'] ) < 18;

	if ( $is_adult ) {
		$notification->data['first_name'] .= ' (adult)';
	}

	/**
	 * See more here
	 * https://developer.wordpress.org/reference/functions/update_post_meta/
	 */
	update_post_meta( $post_id, $meta_key, $is_adult );
};

/**
 * on update post use this action:
 * jet-engine/forms/notifications/after-post-update
 */
add_action( 'jet-engine/forms/notifications/after-post-insert', $on_insert_port, 10, 2 );