We do not suggest buying from Alibaba due to 1. Shipping times, 2. Authenticity concerns, and 3. Many Alibaba suppliers will not be authorized in Amazon's view.
There are plenty of authorized suppliers in the US that you can find using the methods in the course so Alibaba should not be your first source.
Similar Question Phrasing:
Can I purchase brand name products from Alibaba or other China sites?