iphone locked to owner.

If you are the owner or the owner has shared all information with you then to open Activation Lock:- If it is Activation locked, read here --> Turn off Activation Lock - Apple Support Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Learn how to remove a device from a previous owner's account.

If you are not the owner and do not have the Apple ID and Password then there is no way that you can get into this iPhone unless the original owner shares the Apple ID and password with you. If you are lucky you can get into this iPhone if they (owner) accidentally remove the device from their Apple ID.

How to unlock iPhone locked To Owner?

Contact the previous owner to unlock it with their Apple ID,

If you cannot contact them then you can have it recycled for free at an Apple Store or a recycling centre.

Read the post just above yours.