Hi , I was wondering how do I join the beta programme please
Hi @jpd80 To be eligible customers need an unlocked device (not tied to a specific network) and a Samsung account. Notification of any Beta programme will appear in the Notifications of the Samsung Members app and may be publicised on Samsung channels, plus there is usually speculation on tech sites. Users then need to apply but there is still no guarantee of success. Many devices including the Note 10 Plus already have One UI 2.1 for instance which has been rolled out. There will be an Android 11 Beta at some point which include One UI 2.5. https://www.gottabemobile.com/samsung-galaxy-android-11-update-info-2020/
More details for a previous Beta here Beta Programme
To add to @JAMES4578 advice be aware beta is just that it can unstabilise a phone so I wouldn't suggest to download this on your daily driver.
Best of luck.
Current Phone ~
Samsung Note 20 Ultra 5G SM-N9860_256Gb SnapDragon 865+
Samsung One Ui 3.0/ Android 11.