Once you create the qos map, you should apply it to the logical interface with the IP address, so in this case the PPP interface
Something like qos-policy out <name of QOS Map>
interface ppp 1
qos-policy out VOIP-OUT
Do I have to statically assign the bandwidth of 10 Mbps to the interface? How do I set up to reserve 2 Mbps of bandwidth for VoIP?
The guides Configuring QoS in AOS and Configuring Enhanced Ethernet Quality of Service (EEQoS) in AOS are very helpful and include configuration examples. Do you want to take a look and let us know if you have additional questions?