Maybe something with creating your own mike output digitally? Also, you can trim the track choose the timestamps from which to which SLAM should play the track and change the playback volume.
You also need to choose a bind key for playing a track.
In the current version, you can either do it the old-fashioned way or plug in a YouTube link directly into SLAM, so that it retrieves the audio track and uses it later in the game.
There is a pretty lengthy method of editing audio files to a specific herz format and switching them for an internal voice input file, but this method might as well be considered obsolete.
For example, if you want to add a prefix for the player named OciXCrom that will expire on 20.
Usually, they are controlled with chat commands inside the CS:GO chat.