By default, HTML5 recording is enabled on desktop Safari. However under some circumstances a microphone may not be available to the recorder, even when plugged in. But for most users, it should work fine.
To enable/disable desktop Safari support (on macOS High Sierra and above ), go to:
site administration -> plugins -> filters -> poodll filter -> general settings
In the “HTML5 recorder settings ” section, check or uncheck “Use on desktop Safari”