How to turn off Stolen Device Protection on iPhone in Myanmar?

I am currently living in Japan. Last Week I bought an iPhone and sent to my brother as his birthday present who is living in Myanmar. The problem is that I forgot to turn off stolen device protection. So now my brother is annoyed by entering apple id password whenever he downloads some apps on app store. when he tries to turn off stolen device protection, the face id section only pops up. after that instead of passcode option, it only appears 'learn more'. How can it be turned off from his location?

[Re-Titled by Moderator]