Fastboot Device not Detecting my Device

I'm following this tutorial about how to unlock bootloader on Moto. My device is a Moto G5, and my computer has windows 10. On the command line, I can type

adb devices

and it returns my device. I then do

adb reboot bootloader

and it turns my phone into bootloader mode. But when I do

fastboot devices

it returns a blank line. According to this source (the second answer), I need to update some the "Unknown 'Android' device". However, I don't have anything like that. The closest I have is Other devices->Fastboot potter S. Do I update this driver? If so, how? If I choose "Search automatically for updated driver software," it doesn't find anything. If I choose "Browse my computer for driver software" and then "Let me pick from a list of available drivers on my computer", I have to "Select [my] device's type from the list below." but I don't know which one I'm supposed to choose. How do I fix this problem with fastboot devices? What drivers am I supposed to update? How do I fix them? If this question is better suited on another stackexchange such as superusers on account of it's being more about windows than android, let me know. I tried asking it there first, but the "android" tag said that the question would be off topic.