The name of the form class and the form file must end with "Form"

Problem/Motivation

The file and its class need to be renamed to end with "Form":
web/modules/contrib/phone_international/src/Form/PISettings.php

It would also be better if the beginning of the file and class name contained the full name of the module without abbreviations (for searchability and readability in files where this file or class is mentioned. Additionally, "PISettings" needs to be renamed in all other files where it is found.