How to get the placeholder variable of the international telephone number plugin?

Question

JavaScript

The site uses the plugin https://intl-tel-input.com/
It dynamically displays in the input placeholder without a country code depending on the selected region.
There is a wish of the customer to display input there in the format [phone].
As far as I understand, you need to get the country code in variables depending on the selected flag,
and the placeholder and combine them at some stage.
Or is there a more rational solution?
P.S. I did not find the function to change the placeholder format in the plugin documentation.