Electric bikes are made of exactly the same materials as regular bikes added with electric components. Therefore, maintaining an e-bike is similar to a regular bike. You need to keep the chain lubricated, regularly check the tyre pressure and keep eyes on screws. It is also recommended to keep cleaning the electronic parts, follow the best practices to charge the battery etc.
However, an e-bike creates more friction on chains, brakes pads, wheels and tyres which might wear faster than normal bikes. A good quality electric bikes add very little to the maintenance schedule. It’s a good idea to refer e-bike manual and follow recommended schedule maintenance proposed by the manufacturer.