woocommerce_checkout_fields is not working anymore in new updated checkout page.

Hi, I am a full-stack developer, and it is been a while that, I have customized the checkout page. yesterday, I got a project where I have to customize a checkout page, and I noticed that the WooCommerce checkout page is now updated to a different look and now it has Fieldsets like Contact information, Billing address, and Payment options.

I want to add another fieldset that will have up to 8 fields in it. but woocommerce_checkout_fields is not working anymore. Can you please help me to understand if the filter is being replaced, or if there is a new filter to add a fieldset in the checkout form. Also I can not see the checkbox that ask user to ship to a different address, and only Billing fields are visible.