You keep the full duration included in your code. A two-year code activates for two years; a three-year code activates for three years.
If you activate the code from September 15, 2026, at 11:00 Europe/Vilnius, you must complete automatic-renewal setup with personal/billing details and a payment card. The date you purchased the code does not exempt it from this activation flow.
You are not charged again for the plan during activation. Automatic renewal occurs only after the full activation period ends. It is always for one year at the regular plan price minus 10%, unless canceled; it does not repeat the original two- or three-year duration.
If you use the code to extend an active plan, you must wait until 30 days or less remain. Those remaining days are added to the code's duration, and renewal occurs at the resulting expiry.