title: Amazon SNS with ruby, simple sms message
body: <p>I'm trying to send a simple sms from ruby directly to a phone number with the SNS service.</p>
  
  <pre><code>require 'aws-sdk'
  sns = Aws::SNS::Client.new(region: 'my_region', access_key_id: 'my_id', secret_access_key: 'mykey')
  sns.publish({phone_number: 'my_number', message: 'test message'})
  </code></pre>
  
  <p>but i get <code>ArgumentError: unexpected value at params[:phone_number]</code></p>