@SergejoWizz's answer contains the full location where to change the Docker toolbox start.sh file, however editing the file might not be desired every time, as one might reinstall Docker toolbox or install it on other computers, so you might want to create a temporal file shortcut with the provided
--virtualbox-no-vtx-check parameter below.
Home Edition does not support Hyper-V I was able to use VirtualBox at Home but not docker inside virtualbox with the same message,
yet, even when I upgraded to Windows Pro, I had the very same issue as you in spite of having UEFI (Bios) SVM = AMD-x version of VTX, I had disabled Hyper-V as it is possible only at Windows Pro version, but what seems to help me is running docker toolbox manually via command like this with a parameter
docker-machine create -d virtualbox --virtualbox-no-vtx-check