Forget old accounts apple id, is there another way i can sinc the account to this device?
Assuming you still have the device you should be able to find the ID/email in the device, however Live Support will have to assist you with relinking to a new device.
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If you want to swap your account to a new Apple ID, you will need to provide IGG Support proof of ownership. This is often done by providing an invoice statement or something along those lines.
However, not having the current ID is problematic. If there is another way you can prove ownership, IGG Support can still probably help you.