If anyone would like their phone numbers to format for users as they type them, they can use this module script on the add/edit page.
import { AsYouType } from 'https://cdn.jsdelivr.net/npm/libphonenumber-js@1.13.11/+esm';
$("#x_PhoneNumberField").on('input', function(event) {
const originalValue = $(this).val();
const formatter = new AsYouType('US');
const formattedValue = formatter.input(originalValue);
$(this).val(formattedValue);
});