To upload brand trademarks to Alibaba stores, you can follow the steps below:

First, you need to register as an Alibaba member. If you don't have an account yet, you need to register first.

Log in to the Alibaba seller backend, find the "My Alibaba" or similar page, and then click "Wangpu Management" to enter the store management interface.

In the store management interface, find and click the "Wangpu Decoration" option. This is usually used to customize and edit the appearance and content of the store.

On the decoration page, you can see a variety of editing options and tools. Find the setting area related to brand trademarks or store logos.

Click on this area and select "Upload Image" or a similar option. In the file selection box that pops up, select the brand trademark file you want to upload.

After uploading, you may need to adjust the position, size or style of the trademark to ensure that it is displayed appropriately and beautifully on the store page.

Finally, save and preview the changes. Make sure that the trademark has been successfully uploaded and displayed correctly on the store page.

Please note that when uploading your brand trademark, you need to ensure that you have the legal rights to the trademark and comply with the relevant regulations and policies of the Alibaba platform. In addition, the format and size of the trademark may need to meet certain requirements to ensure its optimal display on the store page.

If you encounter any problems or difficulties during the upload process, it is recommended to contact Alibaba's customer service or technical support team, who will be able to provide more specific help and guidance.