is it impossible to know a Wifi mac address of an android phone via a link? There is someone that I doubt that he uses my stolen phone so I want to make sure that the phone that he uses is mine or not by knowing the Wifi mac address of phone – to see if it's mine or not.

I have used iplogger before but all what it shows is ip address- Android  version - browser - phone model-etc. I just wanna make sure before telling telling the police about this person.

I have already done tracking report, but they did nothing.

What can I do ?? The phone uses Android 5.
An IP logger captures the IP address and the browser user agent string, the browser user agent only contains information like phone model and browser, no uniquely identifying information like MAC addresses.

So no, this iplogger (or any other that uses similar techniques) cannot determine if the phone is actually your's, only if it is the same model, but thousands of that model are sold so that is not considered evidence.