How to return a found iphone to its owner?

I found an iphone 5s and it has a password on it, I'm trying to figure out a way to return it to the owner but I can't call or text because the phone has a password on it, any tips will help, thanks

You don't need to unlock the phone if the owner calls you on that phone. If there's no contact for more than a week, try handing the phone to a nearest lost& found.

You can put a ad in the newspaper- or you can go to a sprint store- cell phone store--and maybe--technician can unlock it and get in touch with the owner--or put a flyer on some billboards in stores- and owner-will see it.

Even though the phone is locked, if Siri is enabled, you can use it to try to find out who the phone belongs to. You can ask, "Whose phone is this?" and it should come up with the name of the owner and possibly even an email address or phone numbers. If that doesn't work, try telling Siri to call mom or dad or even home/house (if the phone has contacts named this) to help try to get in touch with the owner.