Add 10,000 comma separator while filling form

I have a number entry field where the number goes above 100,000,000 (100 million).

How to automatically show the “thousands” comma separator in the entry-box as the user types into it? Or is there a plugin add-on that can help with this?

Having the comma separator makes it easier for the user to check if they have entered the correct number.

Ideally, the comma separator is only for display purposes to the user, while the value being submitted is still in the standard number format (without comma) -> 100000000. But if it has to have the comma, ideally it’d be in text format (so that 100,000 doesn’t get submitted as 100)