If you are using iTunes 12.2 and newer, by default, iTunes no longer shares its library XML with other 3rd-party applications, like BRIO. You will now have to share your iTunes library XML with BRIO manually. To do this:
Click iTunes>Preferences>Advanced, and check Share iTunes Library XML with other applications.
When you go to This PC>My Music>iTunes directory, you should now be able to see iTunes Music Library (XML file Type) visible in this directory. If this is visible, BRIO would be able to scan the iTunes Library and you should find the iTunes audio files under Library in Albums, Tracks, Artists and Genres.
[Note: BRIO Standard supports Apple Lossless (ALAC). Due to AAC licensing, BRIO Standard (server) does not support AAC format. Subscribe to BRIO Mobile plan if you wish to get the BRIO server with AAC support].
Next article: "How To Re-Scan Local Music Library?"