---How can move the Ubuntu system to emmc

Dear all,
My board is Rock Pi 4B v1.4, I have been using SD card to host the Ubuntu 20.04.
Currently I have customized it into my home router with wifi AP. it is working brilliantly.
And now I am planing to move the Ubuntu system to emmc. Please index me to do that

You can follow this guide, https://wiki.radxa.com/Rockpi4/backup .