In the Alibaba merchant backend, you can add watermarks with one click by following the steps below:

1. In "Product Management", click on the edited product template;

2. Select "Edit Product Information - Main Picture and Video Information" in the left menu;

3. Select the picture to be watermarked and click "Add Watermark";

4. In the pop-up dialog box, select the watermark style and position, adjust the watermark size and transparency, and confirm to add it.

Note: The uploaded picture must be in JPG, PNG or GIF format, and the picture size must not exceed 2MB.