/ With postfix Recipes
There are two approaches to add postfix for masked input. Every approach has its own behaviour and requires basic understanding of different core concepts.
By pattern mask expression
#This example demonstrates how to create postfix via dynamic pattern mask expression . Percent symbol is a trailing fixed character, which will be automatically added when user enters the first digit.
By postprocessor
# This example demonstrates how to create postfix via postprocessor . It provides more flexibility, and you can configure any desired behaviour. You can use built-in maskitoPostfixPostprocessorGenerator or create your own.
Don't forget that
mask property should be compatible with a new prefix / postfix! 
Maskito