You can edit your promo banner in the page builder and insert any link in the promo banner. You can then customize the button by editing its text, color and size You can also choose to open the link in a new tab.
See video for understanding: https://youtu.be/7l1hwD6qxvM
Another question, how to enlarge the “add to cart” button, it is too small now, not very eye-catching, I want to make it large. Pls also note the quantity input box should be in coordination with the add to cart button.