To add products to Douyin videos, you need to meet the following conditions:

1. Become a Douyin real-name authenticated user: You need to complete the real-name authentication of your Douyin account.

2. Become a Douyin creator: You need to apply to become an official Douyin creator and pass the review.

3. Have e-commerce qualifications: You need to have legal e-commerce business qualifications, such as individual business owners or business licenses.

4. Carry out product certification: You need to certify the products you want to add to ensure that they are authentic, legal and in compliance with Douyin's relevant regulations.

5. Comply with Douyin platform regulations: You need to comply with Douyin platform regulations, including not involving prohibited content such as politics, pornography, violence, etc., and provide accurate and true information for product descriptions, prices and other information.

Please note that the above conditions may change according to the updates of the Douyin platform. It is recommended that you check Douyin's relevant regulations and requirements before using Douyin's commercial functions, or consult Douyin's official customer service for the latest information.