Enqueue scripts

// Register Script
function _ff_scripts() {

	wp_deregister_script( 'jquery' );
	wp_register_script( 'jquery', 'https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js', false, '3.3.1', false );
	wp_enqueue_script( 'jquery' );

	wp_register_script( 'theme', 'location', array( 'jquery' ), '1.0.0', true );
	wp_enqueue_script( 'theme' );

}
add_action( 'wp_enqueue_scripts', '_ff_scripts' );