If the user’s operating system does not support the needed character, how can the symbol be represented?

Answer 1

I don't think it has to do much with OS, instead with encoding. 🤷‍♂️

Answer 2

Use unicode (UTF-8) encoding at head of HTML. Or use character code instead of not ASCII characters, you can get those here
https://code.sololearn.com/WVmtYolTcDXr/?ref=app

Answer 3

In cases wherein their operating system does not support a particular character, it is still possible to display that character by showing it as an image instead.