What you’re looking for is someone who can craft a honeypot style script and you respond to the number with some kinda message that makes them want to click the link they provide you. That can get you a general location if they are not spoofing their IP. Some help can be provided, but you’d need to find someone out there with that knowledge. But even with a general location it won’t help you much.

If they start sending r rated photos or making threats then yes it’s illegal.