There are no exactly square templates that I know of.
When you use File menu, New, there are two tabs. Click on the Comic tab and choose Yonkoma (4-panel, vertical). Japanese-style, not exactly square, but worth checking if you meant panels rather than squares.
I have put up a horizontal comic strip template here. Western style, 3 or 4 panel with choice of joined panels. Again, not exactly square.
Lastly, you can create and edit your own comic templates:
- Layer menu, Add Panel Material (adds a frame for the whole page)
- Use the Divide tool (knife icon) to divide the frame into individual panels
- Use the Operation (Object) tool to edit panel borders.
I am not sure what you meant by “fuel tool” – further details?
-Obtusity