OnCourse Software

There are some airports where you get runway crossing clearance and some other airport don't get anything from tower for runway crossing clearance.

Is that something to do with a afcad file for that airport?

How do I request runway crossing clearance?

Chungers

Per the manual, section 8.15.1:

"When taxiing to/from the runway if your route takes you over a runway
you will need to obtain clearance to do so. As in the real world you should not
cross any runway unless cleared to do so. New to PFE version 2.9, when
reaching a runway intersection ATC will either clear you to cross or tell you to
‘Hold for traffic’
If you reach a runway intersection and hear nothing from ATC you should
HOLD SHORT of the runway! You may then request clearance to continue
your taxi by hitting hotkey #0 (zero), but you must be stationary and with
TGS ‘active’ for this new request to work."