Add dynamically updating version on file

enqueue-version.php

<?php

/* Whenever the theme style file will update on server, this file version
* will automatically update
* Ref - https://developer.wordpress.org/reference/functions/wp_enqueue_style/#comment-2056
*/

wp_enqueue_style('main-styles', 
                  get_template_directory_uri() . '/css/style.css', 
                  array(), 
                  filemtime(get_template_directory() . '/css/style.css'), 
                  false);