There are some Christian or religious bookstores in the larger cities of Ethiopia.
If you put the words Addis Ababa Christian bookstore or Dire Dawa Christian bookstore in google.com, you will find some Christian or religious bookstores in Addis Ababa.
Here is a list of the largest cities in Ethiopia.
Wikipedia
https://en.wikipedia.org/wiki/List_of_cities_and_towns_in_Ethiopia
There are some Christian bookstores in Addis Ababa.
I don’t recommend false doctrine books such as charismatic, Pentecostal, Catholic, or Calvinist books.