From their readme it looks like you can host it however you want:
> Appwrite backend server is designed to run in a container environment. Running your server is as easy as running one command from your terminal. You can either run Appwrite on your localhost using docker-compose or on any other container orchestration tool like Kubernetes, Docker Swarm, or Rancher.
> Appwrite backend server is designed to run in a container environment. Running your server is as easy as running one command from your terminal. You can either run Appwrite on your localhost using docker-compose or on any other container orchestration tool like Kubernetes, Docker Swarm, or Rancher.