Is there a way to remove Activation Lock on an iPhone X purchased from Facebook marketplace?

Hello~ No…we can’t help and neither will Apple as you are not the original owner. Obviously he did not prepare the iPhone properly to resale. Your only choice is to contact the person who sold the iPhone to you and if they can’t/ won’t remove the activation lock you can recycle that device responsibility. There is also the chance that you bought a stolen iPhone.

~Katana-San~

Nope. Without the assistance from the original owner, you have a device that will never be able to be used. See this support article about purchasing used devices.

The All Too Common SAD Reality of Buying … - Apple Community

You will not be able to get the Activation Lock removed without providing the original purchase receipt from Apple or Authorized Apple seller. You actually don't even know if the device had been stolen and the person you bought it from was even the original owner. Any receipt from a third party will not be accepted to remove an Activation Lock.

Hello~ No … they can’t as *Mac Jim ID* correctly points out that Apple doesn’t get involved in third party sales transactions. Your only option is to contact the person you bought it from and hope they can help you …otherwise recycle the iPhone in a responsible manner because you will not be able to use it. Sorry…

~Katana-San~

Nope. Apple does not get involved in third party sales.