He has been patient enough not to launch the first beta version of iOS 12 for developers, knowing that a public beta will follow. The good news is that iOS 12 public beta 1 is now available for download, and you can get it on your iPhone or iPad without too much trouble.
But because we're looking for unfinished software, you can expect specific errors and stability problems to affect your overall experience. The good news is that you can still degrade from public beta 12 from iOS to iOS 11.4 in the easiest way, without losing any data.
The first beta version of iOS 12 was much more stable than I would have anticipated, and shows that Apple is looking to improve the quality of its software in the future. You can run iOS 12 beta quickly on your main phone or tablet without worrying too much about errors and stability issues. But you could always want to re-flag the software on iOS 11.4, which is Apple's latest final iOS release for the public.
There are two ways to downgrade your software and not lose data, depending on whether you regularly support your phone and tablet or not. Ideally, he endorsed his installation of iOS 11.4 on iPhone or iPhone before through the public beta update of iOS 12. If that is the case, simply follow these instructions. You will need the Windows or Mac computer that was used for the backup, in case you prefer local backups. If you use iCloud for backups, you still need a PC with iTunes to downgrade your software.
While it's a good idea to back up your iPhone regularly, you may have jumped into public beta 1 of iOS 12 without backing up the phone first. If that is the case, then you should know that you can still go back to iOS 11.4 without losing any data.
You'll need iTunes to do it, so go find a computer and a Lightning cable. You will want to download the version for iOS 11.4 that matches your iPhone or iPad model, the IPSW file. Simply go here and find the appropriate software.
Once the download is complete, you will have to put your iPhone or iPad in DFU mode, following the instructions available here. When you are finished, connect your iOS device to the computer mentioned above and go to iTunes.
Inside iTunes, go to the iPhone or iPad section and look for the Update button. Press it while holding the Option key on Mac or the Shift key on Windows to access a menu that will allow you to select the IPSW file that you just downloaded.
That's all you have to do to get away from the public beta of iOS 12 1 and back to iOS 11.4 without losing any data. Rinse and repeat each time you want to return to a stable version of iOS from a beta version. The last iOS 12 will be released in September, so we will have many beta tests until then.