To use Discord on Xbox console, you’ll first need to be an Xbox Insiders member. To do this, you’ll have to launch your console, then do the following:
Press the Y button on your controller
Then type Xbox Insiders and then download the program
Once installed, launch it to register as an Xbox Insiders member
After signing up, just press the Xbox button on your controller, then go to Groups and Chat. Now click Try Discord Voice Chat on Xbox. You’ll be able to scan a QR code which will launch the Discord and Xbox apps to log in and link your Discord and Xbox accounts. If you have already linked your Discord account to your Xbox, it is necessary to link them again.
Once your Discord account is linked to your Xbox, you can join the group of your choice. On the Discord mobile app, you'll see a new Join on Xbox option appear. You need the Xbox app to transfer voice chat from your Discord account to your Xbox.