How to track IP Address of people who fill out a form using HTML?

I’m currently working with my website where people download the software in our company. But they have to enter their name, email or phone to get their feedback in our software. But people fakes their their email, so I want to get their IP address to know how far our software can go. Thank you

Make certain to carefully consider the GDPR, Privacy and PII implications, and to cover what you’re doing in your privacy policy and terms of use.