After VirtualBox Ubuntu Fastboot VIM3L fail , it just stop in the u-boot

When I got the VIM3L.
I Burned the android image into the sd card by “balenaEtcher tool”.
It is work. and I go into the Android system ^_^!

Then, I want to build the android code by myself.
So I follow the step to build a ubuntu area by the Virtualbox.

After Build image.
I found the Virtualbox to burn image is very difficult ><.

sudo python3 u-boot_kvim3l_noab.bin 
fastboot oem format
fastboot flash bootloader u-boot_kvim3_noab.bin
fastboot erase bootenv
fastboot reboot bootloader

then, I start fastboot to burn the image.
but the fastboot stuck at the following

fastboot flash super super.img

After re-start the VIM3L.
VIM3l just stop at the u-boot. can not go into the android.
Even if I re-burn the SD card with the tool it didn’t work QAQ.

fastboot always stop here @@…

Could anyone help me @@?