Over half of our alumni medical missionaries are DOs and they serve in a multitude of countries. There are some nations that incorrectly categorize a DO as a chiropractor and so those do not work for a DO If you have a specific country in mind, do a web search for that. Here is a link that has some information though it may not be up to date:
Answer from John McVay with In His Image Medical Missions.
If your country of interest is not yet granting unrestricted practice for a DO, the AOA desires to engage with your assistance and local “champions” to make a way forward.
Here is a link to a list from 2006 which does list countries and gives a helpful explanation of why sometimes licensure is denied. https://forums.studentdoctor.net/threads/can-dos-practice-internationally.322218/