Gaming in any capacity can be an expensive hobby. Luckily, you can join the Xbox Insider program for free — though what games and programs you’re given access to will vary based on your level within the program.
To join, all you have to do is download the Xbox Insider Hub to your computer or console and log in.
For downloading on an Xbox, navigate to the store and then type “insider” into the search bar. Select “Xbox Insider bundle” and download it to your console.
Source: https://www.distractify.com/p/how-to-become-an-xbox-insider