The frame (also called serial) number is the unique physical number of your bike.
You can find the frame number underneath the bike, below the bottom bracket. You should find a sticker with a QR code and a code starting with CBFM (CowBoy FraMe).
You will also be able to find the code in the Cowboy app after you've activated your bike. Go to Settings --> Advanced --> It's the code under "Serial Number".
An example of a frame number is CBFM18A00967.
A Mac address, also called media access control address, is a unique digital number of your bike.
When receiving your new bike, the Mac address is noted on a wrap which you can find on the frame of the bike. You'll need to scan this QR code to activate a brand new bike.
When your bike is activated, you can find your Mac address in the Cowboy app. Go to Settings --> Advanced --> It's the code under "Mac address"
An example of a Mac address is F7:0B:04:08:78:28