Regex: /^[0-9\p{L}.,\s]+$/u
I would like to replace the characters not matching with the regex with "".
>Solution :
As I understand, you simply want to drop all chars not matching your regex. So the idea is to invert the class of chars:
/^[0-9\p{L}.,\s]+$/u should become /[^\d\p{L}.,\s]+/gu (I added the ^ after the [ to say "not in this list of chars" and replaced 0-9 by \d for digits. Use the g modifier (=global ) to match multiple times.
Running it: https://regex101.com/r/IQz6K5/1
I’m not sure that ,, . and the space will be enough ponctuation. It would be interesting to have a complete example of what you are trying to achieve. You could use another unicode character class for ponctuation if needed, typically with \p{P}. See more info about unicode classes here: https://www.regular-expressions.info/unicode.html#category