EG25 forwarding CCFC in Volte

IoT Modules LTE Standard Module
1

I have modem EG25GGBR07A08M2G connected to network (attached and ims connected):
+QCFG: “ims”,1,1

Voice call and its reception works well.

I’m trying to configure voice call forwarding number, example:
AT+CCFC=2,3,“+…”,145,7,0,128,5 / AT+CCFC=2,3,“+…”,145 / …
then
AT+CCFC=2,1,“+…”,145,7,0,128,5 / AT+CCFC=2,1,“+…”,145 / …
(I tried different combination of settings)

no matter what I try I receive error each time: “+CME ERROR: unknown”

So my main question is if this is possible to set forwarding once having terminal via 4G/VoLte. If possible, then what could be the reason that such configuration its rejected.

2

Please confirm with the operator that the SIM card has enabled the call forwarding service. Otherwires, the configuration will not be successful.