change battery iPhone 11 Pro

Hi,

my iPhone is completely dead, apparently it has a generic battery ( stupid me believing the seller it would have an original one) I can't switch it on anymore ( the last info I received on that phone was that battery couldn´t get recognised...) I removed the phone from the find my section in my cloud - it had an 30days waiting period before getting removed. 30 days are over - it does still show in the find my section, which means that it wouldn´t allow to change the battery and replace it with an original one, right? I´ve had bad experience with changing to another generic battery, the process damaged the phone.

If I´m correct an erasure of the phone from the Find my section wouldn´t help either, cos the erasure does only happen if phone goes online again , but my phone is DEAD. Erasure has pending status only and the activation lock wouldn´t be turned off, right?

Is there any possibility to resolve this problem???? Thanks so much in advance for any help! Carola