The font size on Alibaba can be adjusted through CSS style sheets, but there may not be a direct font resizing function in Alibaba's online editor. However, you can use other editors such as Word, etc., and then copy it to Alibaba's editor.

In addition, you can also adjust the font size through HTML tags, such as using the "<font size='3'>" tag to set the font size to 3. In short, although Alibaba's editor may not have a direct font resizing function, you can still achieve this requirement through other methods.