Great tutorial on setting up a self hosted instance of simplex (npub1exv…d828) .
For any less experienced users who want a virtually point and click experience you can also set up this service on a Start9 (npub126n…e9ll) server as Liberty on the Rocks (npub1p7w…rnqw) just mentioned below.
If you run into any trouble, there is also amazing and lightning fast customer service.