How to construct python command for Unreal python remote execution(String or JSON?)

Having trouble figuring out how to construct python command for sending to unreal’s remote execution api, in string or json or other format?
And I can’t even find a proper documentation on this function on unreal’s website.
If someone can point me to a already exist solution or documentation would be nice.
Such a cool feature but I’m surprise how little I can find on this subject, documentation or discussion.

absolutely undocumented feature. annoyed i have to spend time trolling around for a simple working example. come on, epic.