I want the letters of a string to be replaced with other alphabet using random module which includes recursive function [on hold]

Write a recursive function that accepts a name as input and replaces each letter in the name with a random letter in the alphabet. For instance, given the name "Anu," your function could return "Npx."

​If letter is capital it should be replaced by only capital letters, and the replaced letter should be done in such a way that it comes after the existing letter in the alphabet. For example, "Anu" can be "Bpw" but not "Bmt." I expect the code should include recursive function. This has to use random module for selection of alphabet.