There are holes long the bottom of the frame (not the axel) for pegs on the S1. I have the ones below. I don't advice anyone standing on them with full weight, since it could bend the frame, but are fine for passenger foot placement.

https://www.amazon.com/Motorcycle-Rearsets-Footrest-Footpegs-Universal/dp/B071J1DMTD/ref=sr_1_4?dchild=1&keywords=super73&qid=1591033584&sr=8-4