Or another solution for the following question?
I'm looking for a solution to let my costomer choose between a package with of without track and trace. Without is a bit cheaper, but some customers want to pay extra to track their package.
In Magento 1 I use the extension WebShopApps MatrixRate and here there is an exttra field where you can leave some information which shows at the checkout.
I prefer to use as less as possible extensions i Magento 2, so I'm hoping to find a solution which will be easy and (close to) standard.
That module has version for Magento2 and it's free.
I guess these links should help: