[Q] can we sign a zip to be flashable through stock mi recovery? topic

I would like to know that how r ota zip files of mi devices r signed so that they r flashable though mi recovery, can we edit that ota zip with our files with editing the updater script.
I am asking bcoz no custom recovery is available but I hav ota file and I want to root with mi recovery so I will copy su file in zip and will edit the updater script so that the official signature is not removed and will root the phone...