As of my last update, OpenAI has not made GPT-3 available for direct installation or running on private servers. GPT-3 is accessed via an API provided by OpenAI, meaning that you can call the model over the internet from your applications, but the underlying model itself runs on OpenAI's infrastructure.
However, OpenAI has released some models (like GPT-2) that can be downloaded and run locally. If you're looking for a model that you can run on