Request Header Parser, is IP address okay?

Hello everyone :wave:

I’ve finished my Request Header Parser, you can check it out here:

Project: simple-request-header-parser.herokuapp.com

Source Code: github.com/sitek94/request-header-parser

It seems that it’s working fine but, the IP address that I’m getting looks like this:

{
  "ipaddress": "::ffff:10.39.172.124"
}

And when I use the freeCodeCamp’s example api I get:

{
  "ipaddress": "159.205.213.169"
}

I’ve done some reading about differences between IPv4 and IPv6 but still can’t figure out why these results are different.

If any one could point me in the right direction I’d be really grateful, thank you! :pray: