There is no specific indication in the available information that a side attachment for a dog trailer is possible on the rear axle of the E-Citybike. The Mi Smart Electric Folding Bike (26 cm) from Xiaomi is an E-Citybike with 3 gears and a weight of 15 kg, but there is no mention in the user manual or the technical data of a mounting option for dog trailers on the rear axle.

For a safe and suitable attachment of a dog trailer, it is advisable to enquire directly with the manufacturer or a specialist dealer, as the design and safety of such attachments are crucial.