On my Pi 4, I installed RaspiOS from NOOBS and configured everything. I
installed to the 16 GB SD card which was supplied, but there isn't much free
disk space so I'd like to copy the image to a 32 GB card and use the extra
16 GB on that card as root filesystem.

Using Windows, I've copied the image from the 16 GB card to a .IMG file, and
then from that .IMG file to the 32 GB card, using Win32 Disk Imager (should
I be using a different tool to do this?).

The Pi boots fine. df -k shows that the root partition is still 16 GB, as
I'd expect.

I run sudo raspi-config and select Advanced | Expand Filesystem - but I get
an error "Your partition layout is not currently supported by this tool. You
are probably using NOOBS in which case your root filesystem is already
expanded anyway".

How do I proceed from here? Will I have to start from scratch, putting NOOBS
on the 32 GB card and then installing everything again. Or would a different
disk imaging tool create the 32 GB card in such a way that raspi-config can
expand the filesystem?

--- SoupGate-Win32 v1.05