Write oem file wich included in the File And Flash This Firmware In Upgrade Mode
STK-L21A 10.0.0.214(C10E3R3P1)_Firmware_EMUI10.0.0_05015UPS
STK-L21A 10.0.0.209(C10E2R3P1)_Firmware_EMUI10.0.0_05015UPS
STK-L21A 10.0.0.217(C10E3R3P1)_Firmware_EMUI10.0.0_05015UPS
STK-L21A 10.0.0.204(C10E2R3P1)_Firmware_EMUI10.0.0_05015UPS
STK-L21A 10.0.0.202(C10E2R3P1)_Firmware_EMUI10.0.0_05015UPS
STK-L21A 9.1.0.281(C10E2R3P1)_Firmware_EMUI9.1.0_05015UPS