Error message when attempting to clone bootable Qubes USB stick

I purchased a certified copy of a bootable QubesOS USB stick.

I want to clone the certified Qubes USB onto a more compact USB stick.

Both the original and the compact USB sticks are 32 GB in size.

I ran the following command:

sudo dd if=/dev/sdb of=/dev/sda status=progress bs=1048576 conv=fsync

After a significant delay, I got the following error:

30778851328 bytes (31 GB, 29 GiB) copied, 4584 s, 6.7 MB/s 
dd: error writing '/dev/sda': No space left on device
29359+0 records in
29358+0 records out
30784094208 bytes (31 GB, 29 GiB) copied, 4692.9 s, 6.6 MB/s

What should I have done to avoid the error message?

You can’t copy to another USB key if it’s smaller than the original. That’s why you get the No space left on device error.

Also, I’m curious to know where you purchased a “certified copy of a bootable QubesOS USB stick”?

I purchased a laptop from NovaCustom, a certified hardware provider. One of the options that I selected was a USB with a copy of QubesOS, in case I needed to reinstall. The USB is labelled Qubes OS (certified).