Yes! Oliver pulls in your product data directly from WooCommerce, but also adds a barcode field to the product page. Once you have a barcode added there, this will sync to your POS and/or Kiosk and be available for use with your barcode scanners. This can be a UPC, EAN, or any numerical 2D barcode you generate yourself.
As long as you have a barcode scanner and your products have a valid barcode reference in your WooCommerce shop, you will be able to search products using their barcodes and add them directly to cart in POS and Kiosk.
When you install the Oliver Plugin, you will see a barcode field under products in WooCommerce. If you populate that field, you will be able to scan the code in the POS!
If you want to add barcodes in bulk, what you can do is export a CSV of your products from WooCommerce. In the CSV you will see the barcode field - you can input all the barcodes in the CSV and import it back to WooCommerce.