How to contact an owner

Hello ~ That is the activation lock. If the person/persons that you bought the iPhone from cannot or will not remove it …the iPhone is basically useless to you. If they cannot/will not remove it…return it and get your money back. We cannot help remove it nor can Apple. Take a look here…

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Also…

The All Too Common SAD Reality of Buying a Used iPad/iPhone

~Katana-San~

Apple can't do this for you (and no, nobody on this forum can either since we are just users like yourself). Unless the owner has left contact information as a message then the device is probably useless to you. You may even have been scammed with a stolen device. See if you can get a refund.