Instead of being a dick you could have searched for "Alexa set volume to a value less than 1" on Google. Multiple reddit threads with exactly the same problem.

Instead of being a dick you could have searched for "Alexa set volume to a value less than 1" on Google. Multiple reddit threads with exactly the same problem. Have you actually checked that "Set volume to 15%" will set it to 15% in the Alexa app?