sgf_load_scripts.php

<?php
function sgf_load_scripts() {
	$dir = __DIR__;

	$script_asset_path = "$dir/build/index.asset.php";
	if ( ! file_exists( $script_asset_path ) ) {
		throw new Error(
			'You need to run `npm start` or `npm run build` for the "create-block/simple-guten-fields" block first.'
		);
	}
	$index_js     = 'build/index.js';
	$script_asset = require( $script_asset_path );
	wp_register_script(
		'sgf-script',
		plugins_url( $index_js, __FILE__ ),
		$script_asset['dependencies'],
		$script_asset['version']
	);

	$fields = apply_filters( 'sgf_register_fields', [] );
	$data   = [
		'fields'      => $fields,
	];
	wp_localize_script( 'sgf-script', 'sgf_data', $data );

	wp_enqueue_script('sgf-script');
}
add_action( 'admin_enqueue_scripts', 'sgf_load_scripts' );