How to Flash new Firmware

I have vim3 pro default firmware is android 9 but I need to flash linux fimware but I cannot success by official guide by khadas I need to know how to do.

Hello Dear,

Welcome to the community.

Can you please explain what is the error you’re getting? And where are you getting stuck from the official tutorial.

I think the tutorial explains everything clearly. If you can share the error then someone can try to help you with it