Hi,
I’m Netalee from Wix Stores- hope i’ll be able to help.
Not sure i understand what you’re trying to do - what should appear in the qty field?
In general, if you want to use the native product page and to change things on top of it (rather than building from scratch) you can use ‘Get Product’ API to get the current product.
In the Product Page settings inside the Editor you can set it not to display the qty and add to cart button
https://cl.ly/5f7daebaa563
This way you can create you own qty and add to cart button (using ‘Add to cart’ api)
Thanks