Missing documentation on how to use proxy with auth based collection selection

[despens]

I would like to activate the selection of a collection in proxy mode via proxy auth. In this mode, a user would access a pywb instance via proxy, and instead of getting to a pre-configured default collection, the collection could be selected by typing its name into a proxy auth dialog.

The documentation doesn't explain how to activate this mode.

Describe the solution you'd like

I'd like a proxy mode in which the collection can be selected via proxy auth. As far as I know this mode exists but remains undocumented.

Describe alternatives you've considered

I am currently setting up multiple instances of pywb, accepting connections on different ports, each with a different proxy configuration. These pywb instances then use the memento and cdx apis to access different collections on my main pywb instance. This seems overkill 😅