How to remove the first character in input if the user entered an extra one in ngx-mask?

Question

Angular

I use ngx mask to enter a phone number with a mask like [phone]. I don’t understand how to make it so that if the user enters an extra character, it is inserted but the first one is deleted.
Here is an example
. For example, the user entered [phone], then presses 6 on the keyboard and the input becomes [phone], then presses 5 and the input becomes [phone] and so on more.
Maybe someone faced similar kind of problems?