Lost iPhone

Hey everyone! hope you all are doing well and are safe at your homes in this pandemic. I'm writing this in regards to the issue that I faced almost an year ago but still didn't got any solution, so I thought anyone of you could help me in this.

So it was a day when my dad was driving his cab and an old man came into cab and was going to South Delhi, India. So my dad dropped him but later on my dad found out that there is an iPhone at the backseat and when he looked at it so it was an iPhone X or maybe Xs idk actually, so my dad told me about this so I just got scared by hearing of a lost iPhone so I quickly arranged a charger for the phone and turned it on and it was on for about 3 months, I charge it daily and let it on without doing anything and just waiting for someone to call on this phone so that I can return it, but no one called, so I turned it off and it's been almost an year, no one has come up to claim this, but one day my mom and my lil sister started putting some random passcodes to unlock it but then it showed me up to connect to iTunes so I installed iTunes in my laptop and connected it, so it gave me an option to reset the phone so I did but now when I'm turning it on it is asking me for the Apple ID and Password of that person which I don't know, we don't even know that person. Now I'm stuck at the same screen and do not know what to do now.

So I request anyone of you to please help me out either le me know how to get rid of this or how to use it for my own use.

Thank You!