Current API looks like this:

POST /-/load
{"url": "https://s3.amazonaws.com/til.simonwillison.net/tils.db", "name": "tils"}

It would be useful to support an extra "headers": {..} optional key which can be used to pass additional headers to use when fetching from the URL, e.g.: {"url": "...", "headers": {"Authorization": "Bearer XXX"}}