Hello,
There is no option in theme settings available to set the columns at the products more than 2. Navigate to Theme Settings > Products Grid > Products columns on mobile.
But under the WoodMart Theme, using the Theme’s Layout Builder you can create Custom Layouts for WooCommerce pages like Shop, and Category. You can use that to create your own custom layouts for these pages. You need to edit the product archive widget and set the products column on mobile 3.
See Screenshot for better understanding:https://ibb.co/hR2Pc5mC
Further, you can read more about the Layout Builder here: https://xtemos.com/docs-topic/woodmart-woocommerce-layout-builder/
Best Regards,