Enable Bulk Variations for a variable Product
Just go to an existing variable product or create a new one. In the Product Data panel you only need to activate the Bulk Variations via the checkbox. After that you will see a new tab in the panel Bulk Variations, here you can set some options like position, layout, enable the search-able dropdowns etc..
Using with a page builder plugin (Optional)
When using a page builder plugin like Elementor and the WCBV widget does not appear, you need to use the shortcode [wcbv] and place it anywhere in your product page.
The Bulk Variations plugin has some global options. These can be changed via WooCommerce > Settings > Bulk Variations tab.
If you are using the WPML plugin, you can easily translate every label here as well.