A Belt Drive is a great option for an eBike but does not work with every available motor configuration due to a variety of limitations. A Belt Drive system requires no maintenance or lubrication and is rated for 10,000 Miles before it needs to be replaced. A chain should be replaced every 1,500 Miles or so and does require regular cleaning and lubrication.
You can see all the models that feature the Gates Belt drive here: https://www.evelo.com/evelo-difference/gates-carbon-drive/
Take a peek at this video that explains the belt option with a bit more detail: https://www.evelo.com/blog/video-gates-belt-drive-for-an-electric-bike/