We are new to Odoo and are testing the different modules to figure out how to set Odoo up for our company. One issue we have is that we don't always ship out consecutive serial numbers. When we make a sales order, it automatically picks the products with the next serial numbers which are in stock. Instead I want to be able to scan which serial numbers goes to that order.

I found some suggestions that I should go to Settings > Technical > Sequences but can't find this in Odoo 15. 

Any suggestions?