Package UXP (.ccx) with terminal?

I've tried this and was only met with errors: https://www.npmjs.com/package/@adobe/uxp-devtools-cli

Otherwise, is there a tutorial on how to package an .ccx file properly for it to work with installation? The intention is to simply package and sell exculsively without distribution. I've figured out the filing system (to my knowledge), but just need to be able to package a .ccx properly. I've tried change a .zip to a .ccx manually but was also met with erros, presumably.