https://wccftech.com/heres-how-to-join-the-phantasy-star-online-2-xbox-cbt-from-outside-north-america/

The Phantasy Star Online 2 Xbox Closed Beta Test is due to begin this week for the North America region (the United States and Canada). SEGA already clarified there'll be no region locking of any sort in the final game, but you still have a setting to change if you live elsewhere (such as Europe) and want to try the Phantasy Star Online 2 Xbox CBT.

Essentially, to enroll in this test phase (opening on Friday, February 7th at 5 PM Pacific Time and closing on Saturday, February 8th at 11:59 PM Pacific Time) you simply need to install the Xbox Insider application on your console, launch it, look into the 'Insider Content' tab and then select the Phantasy Star Online 2 Xbox CBT under 'Games'. However, if you've set your Xbox One's default region anywhere but the USA and Canada, you won't find the game there.