Clock

Make sure of the day you are selecting and the time AM or PM, after that, check of the alarm sound and how many times it will repeat. Also, check the volume of sound ( press on Alarm sound and check please )

And check that ringtone have sound or not

Thank you for contacting Samsung KSA

try to clear cache and data for alarm app from the device settings-apps-select the app-storage-clear cache and data

tun off auto optimization from the device settings-battery and device care

and from the alarm app add new alarm and check alarm sound option and vibration option too

Clock app -Tap the 3 dots in the top right -Settings -Vibrate For Alarms and Timers, and toggle this option OFF