I want to use a PostgreSQL server that i already have setup, do i need yo use Supabases?

I don't know how easy it will be, but it is mentioned here: https://supabase.com/blog/2021/03/31/supabase-cli#self-hosting

Thank you, well, Supabase site dosnt load when I go to the app.supabase.io, it works on one Mac, but not my other 2. Is it safari?