Unlock phone fastboot

Hello
I try unlock phone use adb & fastboot

Code:$ adb devices
List of devices attached
LHTDU16926003593 deviceCode:$ adb reboot bootloaderok, phone is in mode fastboot&rescue

Code:$ sudo fastboot devicesshows nothing

When I try the whole procedure again
Code:$ sudo fastboot devices
??????????? fastbootphone - huawei cam L21
my linux distro - kde neon

Code:$ lsusb
Bus 001 Device 003: ID 0a5c:21e1 Broadcom Corp. HP Portable SoftSailing
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 007: ID 18d1:d00d Google Inc. Xiaomi Mi/Redmi 2 (fastboot)
Bus 003 Device 107: ID 046d:c077 Logitech, Inc. M105 Optical Mouse
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hubCode:sudo fastboot oem unlock code
< waiting for any device >