Are you in the alarm screen when you tried adjusting the volume? You should notice that when your press the volume button, there's a clock icon beside the volume bar.

That volume "button" is already at maximum. That also controls ring tone. The ALARM app has no volume control itself.

The volume buttons are the buttons on the left side of your phone. So go to Alarm then press volume buttons. Let me know if that works for you.

Dear Carl P:

Where do you find the volume buttons? Have you opened the alarm app yourself? There is no volume indicator.  The options are World Clock; Alarm; and Stop Watch. In the settings dialogue box you will only see "Delete". Check it out.

Hi there. Open the alarm app and press volume buttons to adjust it.