Serial numbers how to have them in Tryton

We have some products that require serial numbers.

I imagine that to do this, I have to install the “stock_lot_unit” module in my tryton. But, how should I proceed to be able to configure my products and ask me for the said serial number when buying or selling?

Lots are not define when selling or buying but when moving stock quantity like on shipment reception or delivery.
For each product you may configure on which kind of location the lot is required when moving from or to.