@Jem I’m assuming they’re available in the UK. I didn’t see your instance name until just now. So, assuming that, I’ll paste the URL at the end. I’m a developer so I can’t test it fully from a public beta POV, but I’ve been both a public and dev beta tester. Login with your Apple ID and download a “profile” with the device you ant the beta software on. Once the profile is installed then you can install the beta software.
https://beta.apple.com/sp/betaprogram/