Hi,
The billing and shipping addresses are not based on the payment plugin but based on the weight of the products in the cart.
If the weight is 0, no shipping method selection is shown and no shipping address is asked.
So, you would just put a weight on your products and that would display the shipping address interface on the checkout. If you don't need to display shipping methods selection, you could remove the "shipping_" view from the checkout workflow option of the checkout tab of the configuration.