If not placed on the market (by means of distance sales) by yourself, you might use an affiliate or a distributor to do so. In the MDR 2017/745, Article 2, the distributor is defined as “distributor means any natural or legal person in the supply chain, other than the manufacturer or the importer, that makes a device available on the market, up until the point of putting into service”. Thus, it is not excluded that the distributor uses an online shop to do so, however it must be clear that the distributor is the seller of the medical device. The same would apply if the affiliate selling the medical device over online shops or alike, qualifying for distance sales.