Yes it is, @Ory Drilon but RTMPE is less secure than RTMPS. For the best security for RTMP streaming, we recommend the Wowza StreamLock AddOn. That is why we send you to that page to get the SSL certificate. Sorry for the confusion on that.
But, to your original question on RTMPE,
Once the module is copied to your Wowza /lib directory and you have restarted Wowza Streaming Engine then you can test playback using the Test Player in the Engine Manager. Use the Adobe RTMP player, and ensure that you change rtmp:// to rtmpe:// in the Server input box. You can test rtmpe playback using a VOD or live application (assuming you have a stream that is currently live).
You can also test playback using a player that is compatible with RTMPE, such as JWPlayer,