I'm not clear on what you mean about the API keys. Are you saying that the API keys are missing when a project is remixed? That's usually intentional, and depends on how the starter project is set up. If you want remixes to be possible but not include your API keys, then you can keep them in .env. If you want them to be public and remixed with the project, you could include them in the source.
Maybe you're asking something else. If so, let us know.