To add AJAX filters to your shop page install this plugin and then use the new widgets in Appearance → Widgets.

This is a replacement for:

• https://wordpress.org/plugins/yith-woocommerce-ajax-navigation/
• https://wordpress.org/plugins/woocommerce-ajax-filters/
• https://berocket.com/product/woocommerce-ajax-products-filter/

Our plugin is based on all of the above plugins.