RM500U-EA Using 5G Procedure

I am currently testing one of your product and I have issues to set it up.
I have an RM500U-EA 5G MODEM FW: RM500UEAAAR03A13M2G.
I am trying to set up this on a Linux Router. It seems that I had GSM working but not LTE/5G.

here’s some informations that may help you :
AT+CSQ +CSQ: 16,99
AT+CEREG? +CEREG: 0,1
AT+CGDCONT=1,“IP”,“apnname” this command stays blocked
AT+CGATT=1 +CME ERROR: 0

then I tried to use PPP :

pppd /dev/ttyUSB3 115200 crtscts defaultroute usepeerdns noauth connect ‘chat -v -f /etc/ppp/chat-go’
ifconfig ppp0 ifconfig: ppp0: error fetching interface information: Device not found

daemon.err pppd[XXXX]: Connect script failed
when I run ATD*99#

I have notice that this model was not compatible with MBIM / QMI is there any way to make it compatible?

What is the procedure to use this modem with 5G? thank you

Dear @lis59
Please share the response of AT commands as below:
AT+QNWINFO
AT+QENG=“servingcell”
AT+QNWPREFCFG=“lte_band”
AT+QNWPREFCFG=“nr5g_band”
AT+QNWPREFCFG=“mode_pref”

RM500U doesn’t support QMI and MBIM.