How to configure VoLTE on WP7607

I am using WP7607 to setup VoLTE calls using AT command.

Current Time: 3294 Temperature: 23
Modem Mitigate Level: 0 ModemProc Mitigate Level: 0
Reset Counter: 1 Mode: ONLINE
System mode: LTE PS state: Attached
LTE band: B7 LTE bw: 20 MHz
LTE Rx chan: 2850 LTE Tx chan: 20850
EMM state: Registered Normal Service
RRC state: RRC Idle
IMS reg state: No Srv

PCC RxM RSSI: -67 RSRP (dBm): -96
PCC RxD RSSI: -68 RSRP (dBm): -101
Tx Power: 0 TAC: 859A (34202)
RSRQ (dB): -8 Cell ID: 04CC6505 (80504069)
SINR (dB): 5.4

I tried activating the secondary PDP context as well but no success.

+CGACT: 1,1
+CGACT: 2,1
+CGACT: 3,0
+CGACT: 4,0


+CGCONTRDP: 1,5,,,,
+CGCONTRDP: 2,6,ims,,,,

Am I missing anything here?
It will be of much help if you can help me with the AT command steps to configure and activate VoLTE on WP7607 modem.

Much appreciate if anyone help me to highlight basic configuration setup for VoLTE with any of the SierraWireless modem and how can we do IMS client registration. I am activating 2nd PDP context from IMS, but still at!getstatus shows that “IMS reg state: No Srv”

Have any member used SierraWireless modem for VoLTE?

From WP7607 Release note, its mentioned that Generic VoLTE is supported from Rel-9.
Below is extract from release note:

“The WP7607 has received GCF certification with VoLTE. The GENERIC carrier PRI has all VoLTE
configuration for certification, however VoLTE must be enabled at the SKU level to activate it for the carrier”.

Does anyone know what is the at command to enable VoLTE at the SKU level?