Adding additional C# scripts after build (Android, iOS)

Hi, for the project I'm working on right now, I would like to be able to add/modify C# scripts during the game, and don't know if it's possible. I have found a few assets in the store but they only work for Standalone platforms (Windows, etc).

So what I need to do is that I have an editor in which the user can create a code of their own, which then needs to be read by Unity to do things in game. So either creating a new C# script and attaching it to a gameobject, or having an "empty" script in which I write new lines. I thought I had the answer with the Unity-Javascript messaging but this only works in WebGL builds.

Any idea if this is possible, and if it is, how to do it on mobile platforms?