Please help! unbrick K371

I was trying to unlock a k371. When i finished and turn off the phone and on again, this happend

[580] boot verification failled

the phone dont star, boot loop
but the good notice y that i can put the phone in Download Mode.
I need to reflash the phone but i dont have a rom.
I cant make a full flash because the phone is bricked.
Please i need the firmware to unbrick the phone.