Locked E5575s-210

[varduk]

Good morning,
I have:

Found modem : E5575s-210
Model : Huawei AuthVer 4 modem (New)
IMEI : 866887021120806
Serial NR. : E9RDW15A31000207
Firmware : 21.200.09.00.12
Dashboard version : WEBUI_17.100.06.07.12
SIM Lock status : Locked (Card Lock)
Wrong codes entered : 3 (unlock attempts left : 7)


I have tried multiple ways to try to unlock it but I have not been able to, could you help me?
Thank you in advance.

[Valdemaras]

What error did you get on DC-unlocker while trying to unlock it?