Hello,
I really apperciate it if you post your question under this topic. Not only will it help you, but others that have the same problem/s. like this. Thank you
As for this question
If your Graylog server is already setup with Active Directory, the user can log in and it will create a UUID for that user. Just like windows OS does for a new user logging in to a device. That user needs to login. If that user is not in “Active Directory Users and Computers” you can create that user manually and set permission. Take a look at this please.