unlock mp260 with bad imei

i have somes lg k20 plus mp260 but i dont know the original imei, when try unlock with credit the gcprokey show



Using Version...1.0.0.0064
Selected Model GT-I5503
Selected Task TMB Unlock(ADB)

Searching ADB device Please wait..
Device Detected...
SELinux := Enforcing
model:= LGMP260
LG TMB Unlocking Started...
SU Version..2.82:SUPERSU
Device is Secure Rooted..uid=0
Reading Please Wait..
Please Wait while...
Please wait starting task...
Device Sn := LGMP260312ce80
Device Imei := 355XXXXXXXXXXX :rolleyes:
Factory Ver := LGMP260AT-00-V11a-MPCS-US-APR-03-2018-ARB00+0
Server Reply Error := ERR_Retry Repair Original IMEI Then retry.

Fail to check server...RYtBDsBACAK/hEK3Xm1W//+kur00ExIyAW/GcDHQVhZG5dcTD2ih9MsCxJ5o3BpDv739LAuOhpT2/7XyIDJX1Ra3cUd2vQ==
Send ASK Saved := LGMP260312ce80.ask