nokia 3 ‘fastboot devices’ command gives nothing

I have downloaded platform tools and adb-setup.exe which installs adb and fastboot i think,further on opening cmd after clicking shift + right click in platform tools i open cmd and here i typed command ‘adb devices’ which gives device and on typing ‘adb reboot bootloader’ command ,the device reboots and now i type command ‘fastboot devices’ which shows nothing.

Using Nokia 3 device for this and using Windows 10.