Legal analysis: Trademark extension can be processed online.

Legal basis: Article 18 of the Trademark Law of the People's Republic of China. You can apply for trademark registration or handle other trademark matters by yourself, or you can entrust a trademark agency established in accordance with the law to handle it. When foreigners or foreign enterprises apply for trademark registration and handle other trademark matters in China, they should entrust a trademark agency established in accordance with the law to handle it.