If the commerce feature is not available for you, please get in touch with your hoster and ask them to activate the feature. Then, the Commerce feature will be available via the Website Builder. It is not a feature that can be downloaded onto the server.
That is very unfortunate⦠and from a personal standpoint I do not understand this decision by the hoster. Anyway, it is great that you choose to switch to be fully on board with us. That is fantastic!