The IVB API has been removed; any requests to https://efa.ivb.at/ivb/ are redirected to a 404 page (and the subdomain itself now returns the homepage).

The new web interface for trip requests is at https://fahrplan.ivb.at, but I don't think a public API documentation is available; the usual paths (/ivb/XSLT_TRIP_REQUEST2 etc.) don't exist there any more.