It only shows when a backend setting called "Show Billing Fields on Profile?" is turned on, and it's off by default. This particular setting isn't part of the regular Client Config screen admins use day to day — in the current version it isn't assigned to any of that screen's tabs, so it's only reachable from the SuperAdmin-only Site Config page, in its catch-all "non-public" section. In practice, ask your Sprwt contact to enable it if you want a Billing Address card to show on top of the default Shipping Address.