The following will route calls from an OBi, OBiON App, or OBiAPP for PC to the Auto Attendnat of an OBi:
Voice Services -> OBiTALK Service -> InboundCallRoute : {290123456:aa},{ph}
The following will route calls from an OBi, OBiON App, or OBiAPP for PC through a particular trunk of an OBi:
Voice Services -> OBiTALK Service -> InboundCallRoute : {290123456>(Mtrunk):trunk},{ph}
where 290123456 is the OBi, OBiON App, or OBiAPP for PC OBiTALK number and trunk is sp1, sp2, li, etc.
For a more flexible approach, see
Single-Stage Dialing Through Any OBi Trunkand
Single-Stage Dialing Through Any OBi Trunk Using SIP