Compile image builder

I'm trying to compile an image from image builder for my device, the problem arises when I try to save the config files, I do not know what command to use and where to deposit them. someone can help me with this project. Thank you for general questions

If you have something specific, it wasn't very clear to me what you were asking. Perhaps rephrasing would help.

You can include them as custom files.

You can save and reuse your the .config file