Fastboot mode bootloader help s6 edge

[wajahatandroid]

I want to know if my bootloader is locked or not. I used the code to know if its locked or not and the code is not working. Then I tried that procedure of cmd and all that . I just want to know how can I put my s6 edge in fastfoot mode. When I use command adb devices and it shows my device but when I use fastboot devices and it shows waiting for devices. How can I put my s6 edge in fastboot mode and then use fasboot devices command.