In Magento 2 POS screen, you can configure to search products by going to Setting > General. In tab Catalog: Enable Display out-of-stock products in search results by choosing Yes option.
Set up Product Search section in Magento 2 backend to set product attributes for search. In Product Attribute(s) for Search, select attributes by which you want to search products. The default attributes are Name & SKU. If you want to search quickly by barcode, choose barcode attribute. Hold Shift + Click to pick more than one.
In frontend, you can search products by 3 ways, which are categories, product attributes and barcode:
- Use categories: In frontend, you can click on All Categories link to quickly search products by categories. Choose the corresponding categories as you prefer.
- Use product attributes: To search by product attributes, click on Search icon, then a search bar will be shown. Enter your search terms and matching products will display right away.
- Use barcode