Apple on Wednesday released iOS 11 public beta 2, which has the same features as a third developer-only beta that was seeded to developers two days ago.
Before it can be installed on your device, you must sign in with your Apple ID at beta.apple.com in order to enroll your iOS device to access the latest public beta of iOS 11.
Next, from your iOS device visit beta.apple.com/profile to download the configuration profile.
Follow the onscreen instructions to allow installation of the profile, which will permit your iOS device to automatically receive over-the-air public beta software updates.
Lastly, go to Settings → General → Software Update to install the public beta.
Screenshot via Joey Antonini
You’re wholeheartedly recommended to perform a full iCloud or iTunes backup of the device before installing any beta software. Do not install the iOS 11 public beta on your daily driver.