The chain systems fitted to most bikes need lubricating with oil to help them run properly. Over time the oil picks up dirt which makes it run noisily and less efficiently. If your clothes touch the chain they can get stained with dirt.
The Gates Carbon Belt Drive fitted to your Buzzbike-E runs without oil or grease meaning it will never stain your clothes. It will also run near silently and incredibly smoothly for life with virtually zero maintenance. Please do not lubricate the belt with oil. Just clean it with water if it gets visibly clogged with mud or other dirt.