As Google made it impossible to start screens from background on Android 10, we can no longer show the alarm screen with the big buttons with usual settings.

To get full screen alarms in all cases you can do the following workaround:
– set Settings → Alarm default settings → Flip to snooze (depending on your settings might be hidden under Advanced options, in the Snooze/Dismiss section)
– in phone’s Settings → Apps & Notifications → SaA → Advanced → Draw over other apps – enabled this permission..

Issue: When alarm goes off, it does not disable the lockscreen and you have to manually unlock the device to tap snooze or dismiss.

Explanation: You may have Sleep as Android enabled under Border lights. This causes the alarm popup to not display over the lockscreen, as the notification is being shown as a light around the edge of the screen.

Solution: Disable Border lights for Sleep as Android in your device’s settings.

On Xiaomi/MIUI, you need to grant special permission to Sleep as Android so that it may unlock your screen during alarm.

Go to System Settings > Permissions > Advanced Permissions > select Sleep app and give it permission to access Lockscreen.

See https://sleep.urbandroid.org/documentation/faq/alarms-sleep-tracking-dont-work/

Settings for Captchas are set in Settings > CAPTCHA.
Choose the Captcha in Default Captcha – this opens a list of all Captcha. Then set the difficulty of it.
You can also preview the Captcha.

For QR/NFC Captcha, you can learn the code for recognition by tapping the “learn” button in Settings.

For changing the QR/NFC Captcha, tap on Settings below Preview, and then tap “learn” button. You can also delete the old code by tapping the trashcan icon in the same screen.

You always get full screen alarm, when at least one of the following is true:

• sleep tracking is running
• if you have a keyguard (lockscreen) set up
• if you have a Settings > Alarm default settings > Flip to snooze option turned on

It sounds a little hacky, but the reasoning is simple. Some people want to use the heads up notification, it can be convenient if the alarm rings while you’re operating the phone. Flip to snooze is an option that cannot work with notification (it is impossible by design), so if you turn it on, we forbid all heads up notifications and go to “full screen alarm only” mode.

On Android M, it is also possible to turn off heads up notifications per app in Android Settings > Apps > Sleep as Android > Notifications > Allow peeking.

See https://sleep.urbandroid.org/documentation/faq/alarms-sleep-tracking-dont-work/

Alarm ringtone can be configured on two places. Globally for all new alarms in Settings but this may be overridden for each individual alarm in per-alarm settings. Please check both places if you setting is correct.

You are probably using the stamina battery saving mode or Extended Standby Mode which prevents Sleep as Android from waking up the device ans so the alarm will not ring if this mode is enabled.
For stamina mode, you can either disable this mode or add Sleep as Android to the active applications in standby. The option resides in settings->Power management. To add Sleep as Android to the active applications in standby, click on “stamina mode”, then “Add applications” and check Sleep as Android.