QoS for VoIP traffic only

Hello.
I have (2) RB433’s setup. They are routing network data between them over their wireless interface. I could use some help understanding how to prioritize VoIP data over the wireless link versus standard data traffic. I’ve read documentation, etc. but am having trouble understanding how to configure this on my devices. Is there a guide for this, or how-to, or can someone please lend some help? I use the winbox gui for all my configuration so I’m trying to do it from there.

Appreciate any help.
K