Mooncakes from Yiqinfang Provincial Doctors can be purchased online. You can search for "Yiqinfang Moon Cake" or "Provincial Doctor Moon Cake" on e-commerce platforms such as Taobao or JD.COM, and you can find and buy the product. It is recommended that you carefully check the credibility and product evaluation of the store before buying to ensure that you can buy authentic Yiqianfang provincial medical moon cakes.