Normally, to use this field, make sure:

• Track lots or serial numbers is checked in Inventory --> Configuration --> Settings

• Tracking is set on the product(s) for which you wish to define a Warranty.

• Users wishing to manage this field are members of the Manage Lots / Serial Numbers group.

There is currently a bug in the way the field is being added to the product.template.stock.property.form.inherit view. The groups tag is specifying stock.group_stock_production_lot instead of stock.group_production_lot. The former group does not exist. You should report this at https://github.com/odoo/odoo/issues