Should auto link in the near future.You know it has if you see in your profile that your mileage won't expire.
-1
But card is automatically linked up?Correct?Or do I need to link it myself?
Automatically.
Card is automatically linked. In the new United.com https://www.united.com/en/us/ the hovering does NOT show anything about being a member/not expiring. In some places.In classic View, it shows. https://www.united.com/ual/en/us/ .