Zend certified PHP/Magento developer

How to create short cuts for typing special characters in Ubuntu?

I am using the OS Ubuntu 20.04.6 LTS and I have an American keyboard. I need to type from time to time Russian special characters (e.g. ё). Is there way/program that allows me to introduce my own custom shortcuts that will produce printing these characters (e.g. Alt+e+~=ё)? Thx