I cannot remove my Apple ID from my iPhone

You can after you signed out.

You can then wipe the iPhone down => What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support

Hi,

Are you trying to delete your Apple ID Account? If Yes, pls look & read carefully at this link:

https://support.apple.com/en-us/HT208504

Hope this works for you.

Cool Regards