Scenario: Change shipping price using variable parsed by design during checkout. I need to change the final shipping price using some variables sent by phtml checkout.
Eg.
Shipping method 1: cost 33$
Shipping method 2: cost 23$
Shipping method 3: cost 10$
special packaging checkbox (y/n) + 10$ (set it as yes for this example)
assicuration:
I've inserted manually this checkbox, just in design but I need to increment final price and add a simple label that include this on shipment
total should be
shipment total 20$