How to unlock an iPod touch that somebody lost

As has already been explained, you cannot get into that iPod if the owner has protected it from unauthorised access. Apple can't help you and neither can we, even if you are a legitimate Lost property Office.

For more info, see:  Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Only the person who set it up can unlock it. Recycle it responsibly, it will never work for you.

Unless the person who lost it posts a message on the device, you won’t be able to find them.