The Satanic Temple’s online weekly services are free open to the general public. They are hosted on The Satanic Temple TV, and take place twice weekly: Temple Tuesdays on Tuesdays at 9:00pm ET, and Temple Weekend Services on Saturdays at 10:00am UTC. Tuesday services are designed to be more convenient for time zones in the Americas, while Saturday services are designed to be more convenient for time zones in Europe and Oceania.
You can find more detailed information about both of these weekly events on the Satanic Religious Services main website.