Can Drone be set up for a manual workflow without repo account sync?

Is it possible to use Drone manually - without syncing with my repo account?

The kind of workflow I am trying to achieve is one where a fresh Drone install has no projects. I have to add/name projects manually and manually add webhooks to my repo.

This approach means I can use multiple repo providers and I just need to supply a webhook URL and secret

There is no Getting Started guide on the website indicating that you can use Drone this way.

Attempting to launching drone server like this results in a main: source code management system not configured error:

docker run \
  --volume=/var/lib/drone:/data \
  --env=DRONE_RPC_SECRET=super-duper-secret \
  --env=DRONE_SERVER_HOST=0.0.0.0 \
  --env=DRONE_SERVER_PROTO=http \
  --publish=80:80 \
  --restart=always \
  --detach=true \
  --name=drone \
  drone/drone:2

Does that mean you that you cannot run Drone without binding it to a specific Github/Gitlab/BitBucket, etc account?

Does that mean you that you cannot run Drone without binding it to a specific Github/Gitlab/BitBucket, etc account?

This is correct, you need to setup an integration in order to use Drone. We designed Drone to integrate very tightly with the source control management system (e.g. github). Drone relies on the source control management system and API for authentication, authorization, permissions, webhook creation and more. This means you cannot use Drone with a plain Git server. This also means you cannot use a single Drone instance with multiple providers; this was an explicit tradeoff that we made to keep the underlying design and code more simple. So unfortunately we would be unable to support your use case; you would need to install two Drone servers if you want to use Drone with two providers (e.g. Github and GitHub Enterprise)