Missing Partition table error for image built using the Image Builder


I have built a image using the Image builder git repo. Image got built under the repo but when I try to copy the image to a SD card I’m getting a warning"Missing Partition Table" in the balena etcher program. I tried to ignore the warning and proceed but the image is not bootable in beaglebone. Can someone guide me how to fix this issue and proceed further?

By default, the image-builder dumps out a generic RootFS tar file.

To generate that into an image Etcher could use, you need to convert
it into a device specific image:

First extract the file from deploy, it should have a "setup_sdcard.sh"
script in the base directory

Then for a BeagleBone run:

sudo ./setup_sdcard.sh --img-4gb some-file-name --dtb beaglebone

Then you'll have a 4gb image file with the name "some-file-name" that
Balena etcher can write to a microSD card.