Need info for mtk6735 this error

Halo hi,

I need to know how to solve the following log error

1. Power Off Phone , Remove battery , Insert back
2. Insert USB cable. In some cases require hold BootKey

Wait for phone…
Phone found! [ 20 ]
Inital Boot Ok!
BB_CPU_PID : 6735
BB_CPU_NME : [MediaTek] MT6735_S00
BB_CPU_EXT : 0xCA00 , 0x8A00 , 0x0000
Processing BROM stage
Settings for BROM configured!
SecCfgVal : 0x07000000
BromVer : 0x0005
BLVersion : 0x00FE
PreLoader : NOT Active [ Erased ]
BootLdrSS : LOCKED with AUTH
Processing DA stage
DA Select done, will use MTK_AllInOne_DA_v5.1552.01.01
Sending and initialize DA …

Boot Error!

Operation Failed
Elapsed: 00:00:04
Reconnect Power/Cable!

I could see here Bootloader is locked.
The Phone is MEIZU, dont know model no. Has come for Security lock.