force-css-js-to-go-live-immediately.php

<?php


// Version CSS file in a theme
wp_enqueue_style(
	'theme-styles',
	get_stylesheet_directory_uri() . '/style.css',
	array(),
	filemtime( get_stylesheet_directory() . '/style.css' )
);


// Version JS file in a theme
wp_enqueue_script(
	'theme-scripts',
	get_stylesheet_directory_uri() . '/js/scripts.js',
	array(),
	filemtime( get_stylesheet_directory() . '/js/scripts.js' )
);


// Version CSS file in a plugin
wp_enqueue_style(
	'plugin-styles',
	plugin_dir_url( __FILE__ ) .  'assets/css/plugin-styles.css',
	array(),
	filemtime( plugin_dir_path( __FILE__ ) .  'assets/css/plugin-styles.css' )
);


// Version JS file in a plugin
wp_enqueue_script(
	'plugin-scripts',
	plugin_dir_url( __FILE__ ) .  'assets/js/plugin-scripts.js',
	array(),
	filemtime( plugin_dir_path( __FILE__ ) .  'assets/js/plugin-scripts.js' )
);

@sanderlt You can put calls to wp_enqueue_style() and wp_enqueue_script() inside of a function that is hooked to WordPress' wp_enqueue_scripts hook. These examples show how to do that: https://developer.wordpress.org/reference/functions/wp_enqueue_style/#user-contributed-notes