The Tech Specs section of the Ride Smart Frame webpage call out the KMC Z1 Narrow chain. It is a common model that you can source in local bike shops / online, so we do not sell it in the Zwift Shop. If you have trouble locating that model specifically - there are many 3/32" width chains (for derailleur-equipped bikes) of similar spec that will also work fine.
Do not use an 1/8" width chain. You want a 3/32" width chain for multi-geared bikes. Most any chain designed for 8 - 12 speed drivetrains should work, but chains get narrower (and more expensive) as more cogs are added to a multi-speed cassette. A 10 speed chain is a good middle ground for the Ride.
The Zwift Ride uses 98 links. It’s less than the ~114 links or so that’s usually included in the package.