Latest firmwares ( >21.315.* ) don't ask for flash code anymore.
Datalock code is an OEM Code, generated from nvram, like unlock (NCK) code.
You can try in dc-unlocker command:
AT^SFM=1
if the answer will be OK then you can do Reseting OEM Code to all zeros:
AT ^ SETHWLOCK = "OEM", 00000000
or
AT^RESET
Modem will reboot and firmware downgrade/upgrade should be now available.
You can install modded firmware and webui. I have few of them at https://www.mediafire.com/folder/ll9ieqq.../Documents
After succeeded installations of both files go to dc-unlocker once again and give commands:
AT^SFM=0
AT^RESET
For unlocking you can try universal command:
AT ^ NVWREX = 8268,0,12,1,0,0,0,2,0,0,0, A, 0,0,0
Or commands for nvram,
OEM code:
AT^NVRDEX=50502,0,128
NCK Code:
AT^NVRDEX=50503,0,128