Need help to unlock bootloader

[MeZen81]

Hello everybody, I'm here to ask how to unlock vibe k5 note bootloader
when I try to use my Volume Up button in order to select to unlock the bootloader, it wont work. Only the Volume Down button is working, which cancels the command

DEVICE Info

Model: Lenovo k5 note A7020a48 (k52_a48)

Manufacturer: LENOVO

Baseband Version: K52.ROW.V40, 2016/04/19 11:27

RIL Version: mtk gemini ril 1.0

Build Number: A7020a48_S125_160419_ROW

Build Fingerprint: Lenovo/k52_a48/A7020a48:5.1/LMY47I/A7020a48_S125_160 419_ROW

Bootloader: unknown

Java VM: ART 2.1.0

OS Version: Lollipop MR1 (5.1)

SDK: 22

Chipset: MT6755BM

 

[MeZen81]

no answer