PBX KAREL 48, problem with internal number?

Question

ATS

There is an automatic telephone exchange KAREL 48 with an expansion board (8 external and 134 internal lines in total).
Connected the phone to port 133. When calling internally, this number gets one beep (the phone does not ring), and says "You dialed a non-existent number."
Also, this phone is an administrator (the PBX is programmed from it) and one of the external lines is directed to it - everything works, calls from the external line go through, the PBX is programmed ... All other phones work.
UPD to switch the call to number 133 came out without problems.