Possible to add "canonical tag" to categories?

Hi,

Im using categories in my shop to separate different articles of clothing (tees, hoodies, caps, etc).

For example "https://www.duhvoli.com/shop/hoodies" is a category page for all my hoodies.

Google is ignoring these urls and suggests I  "Alternate pages with proper canonical tag"

(it choses the first product page under said category instead)

How can I add canonical tag to category page? 

If it's not possible, what would be best solution to fix this?

Thanks! 

I'm having same issue

Hey, so I was having the same issue for the blogs on my website (due to the categories and tags). The way I solved this was to add some javascript to inset the canonical  link in the header, you can copy the code from here: 
https://luckynightstudio.com/blog/how-to-fix-non-canonical-url-error-from-shop-categories-on-squarespace

hopefully this helps, but if you have any questions let me know.