So as you recommended I'm using this in combination with the Free City States mod, as well as Barbarian and Starting Free Cities, but none of them are converting from Free City to City State, even though I've set the conversion to 100% with the Free City States mod. Any idea how I could fix it?

Thanks

The Starting Free Cities mod works regardless of that line, at least according to my testing.

Thoughts about this red line? https://prnt.sc/6ut1b_9667jD

Starting Free Cities says it is only compatible with Rise and Fall, but I have played it with Gathering Storm also without problems. The original developer just never updated the compatibility.

nvm that I had misunderstood. But I do have another question is it compatible with current version? the mod manager shows not compatible with current version. I ignored that and have played a few turns I didn't find one free city

I'm not certain what you mean.

The Free Cities are controlled by the Free City AI, just as if you lost one to Loyalty.

This cook is just a correction to the setup script.

can ai use it too?