I used to be able to get the CS save feature to work with the compile feature built into the CS file you download from COG (not using the one on CSIDE) but I haven’t tried it out since all the problems with the browsers causing a revamp of the CS package to get everything working again, so I’m not sure if it’s still working as it used to. Would need to try it out and see.
If you need to include images, I’d use CSIDE’s ability to convert images into scenes, then compile the game with CSIDE. I don’t know how to get CSIDE to compile with the above save plug in though, so unless someone has more info on this, you may need to choose between the having images or a save plugin, or mess around with separate image hosting.
Edit: Might be worth also taking a look here. I’ve got some instructions on how to host a CS game on itch. I don’t think it’s changed much since then.