Cannot install pkgconfig information for qt6

I need to install qt6 pkg-config related information to be able to build freeciv from source. I do not need to install freeciv from repo - I do changes to freeciv sources, so I need to compile it.

Problem is I cannot install information to pkg-config.
I have wrote this simple command:

zypper in `for a in $(zypper search -i qt | tail -n +6 | cut -d'|' -f2); do echo pkgconfig\(${a}\);done`

But it complains there is no provider for pkgconfig(packagename).
What I am doing wrong?

There is no such thing. There are various Qt6 modules, and each has corresponding pkgconfig provide. Which exact module(s) do you need? Or you could simply install all qt6-*-devel packages.

I need Core,GUI,Widgets .

[ 6417s] Processing files: qt6-core-devel-6.4.2-1.1.x86_64
[ 6419s] Provides: … pkgconfig(Qt6Core) = 6.4.2

I hope you got the pattern …