How to track iPhone location in real time

You cannot do this unless you had Find My enabled on the iPhone before it was lost or stolen.

If you did have Find My enabled, you can log into iCloud using a Web browser. Note that there are various things that can keep you from seeing a location. Also, if your phone was stolen, it would be a very bad idea to go to any location shown to confront criminals in person. You might lose a lot more than just a phone.