OpenVPN Plugin-Change Encrpytion level

So I’ve been using OpenVPN for a few years and didn’t always use the OMV plugin for it I used PIVPN software which allowed for choice for encryption. But with The OMV plugin I can’t find a choice on the web interface or I server.conf. I’m curious about this because I get much slower speeds now. Also what’s the default encryption on this plugin. Any help is apperciated.