I was born into a Muslim family and must have been circumsized when I was mere days old, so I guess it's no surprise I was puzzled at your question.
If Quora answers (I had to look this topic up) are anything to go by, it's not required though. Again, though, not a fiqh scholar. It seems though that opinions vary on how important circumcision is and when it needs to happen or is required, and people can get very opinionated on this topic.
I wasn't talking about quora.com. I was talking about the Quran itself. The Quran is silent on circumcision. There are teachings and beliefs outside the Quran that are recommended or require such a practice. As I said, it does puzzle me because the Quran is rather explicit about bodily integrity. I understand why it is pushed and required in Judaism (although that practice isn't exactly the same as it was 2000 years ago - they only used to cut off the very tip so that one would almost certainly look uncircumcised these days).