Some stuff from the %settings commands may require you to enable Discord Developer mode, with this mode you can copy ID's of several things like Channels, Messages, roles, or even Users!
Here's how to Enable it:
Step 1
Navigate to Your User Settings (bottom left at PC)
Step 2
Scroll down to the "Appearance" tab and open it
Step 3
Scroll down to "Developer Mode" and Enable it if its off