You need these two scopes to access any of the classic/legacy endpoints that are documented as part of the “HTTP API”:
- Classic API (read only)
- Classic API (write only)
The first one will allow you to GET the api endpoints in /export/...
The second one will allow you to POST the api endpoint in /api/... to create a booking (I had misread your original question and thought you want to import data into some other system from Indico).
That said, these APIs are all VERY legacy and may not support all room booking functionality (I think I wrote most of these old APIs over 10 years ago). Unless that bookRoom endpoint is sufficient for you,.it may be better to look at the requests sent when using the room booking web interface and replicate these (using the “Everything (all methods)” scope).