Hello,

The Quantity selector by default shows on the Single Product page, as you can see from one of our Product from Test Site: https://blackpearlspro.com/woodmart_support/product/apple-ipad-mini-6-wi-fi/

If you want to show the Quantity Input for the Products on the Archive pages then you can go to Dashboard > Theme Settings > Product archive > Products styles > Elements > there you can find the toggle option of Quantity input on product > just enable it from there: https://snipboard.io/e9JQty.jpg

For the Quantity Input to show on Header Shopping Cart widget, please navigate to the Dashboard > Theme Settings > Shop > there you can find the option “Quantity input on shopping cart widget” > just enable it from there: https://snipboard.io/3VfM0b.jpg

Best Regards.