Fastboot Unlock and flash TWRP leagoo M5

[AC Question]

Hey guys. I have trouble trying to unlock my boot loader and install TWRP on my LEAGOO M5. I use SP Flash Tool to flash TWRP but when i go to twrp bootloader then click recovery it says NO COMMAND. I thought my bootloader was locked so i tried unlocking my bootloader but when i try Fastboot oem unlock it says Waiting for device. I also tried Fastboot Devices but nothing came up. HELP