Make sure that your kernel matches the folder name (i.e. folder 5.4.23 = Kernel 5.4.23)

You can check your kernel by logging into your Vyos shell and using "uname -r". Should see something like this:
5.4.243-amd64-vyos

sudo cp /home/vyos/bnx2x.ko /lib/modules/$(uname -r)/kernel/drivers/net/ethernet/broadcom/bnx2x/
sudo /usr/sbin/update-initramfs -u -k all
reboot