Hmm ... It's impossible ;-) This RPM doesn't exist on any FTP server

Provides :
cmake(Qt6Designer)
cmake(Qt6DesignerComponentsPrivate)
cmake(Qt6QQuickWidgetPlugin)
cmake(qt6designer)
cmake(qt6designercomponentsprivate)
cmake(qt6qquickwidgetplugin)
devel(libQt6Designer(64bit))
devel(libQt6DesignerComponents(64bit))
lib64qt6designer-devel
lib64qt6designer-devel(x86-64)
libqt6designer-devel
libqt6designer-private-devel
libqtdesigner6-devel
libqtdesigner6-private-devel
pkgconfig(Qt6Designer)
qt6designer-devel
qt6designer-private-devel
qtdesigner6-devel
qtdesigner6-private-devel

Requires :

devel(libQt6Core(64bit))
devel(libQt6Designer(64bit))
devel(libQt6Gui(64bit))
devel(libQt6OpenGLWidgets(64bit))
devel(libQt6Widgets(64bit))
devel(libQt6Xml(64bit))
devel(libm(64bit))
devel(libstdc++(64bit))
devel(libzstd(64bit))
lib64qt6designer6 = 6.6.2
libQt6Core.so.6()(64bit)
libQt6Core.so.6(Qt_6)(64bit)
libQt6Core.so.6(Qt_6.6)(64bit)
libQt6UiTools.so.6()(64bit)
libQt6UiTools.so.6(Qt_6)(64bit)
libQt6Widgets.so.6()(64bit)
libQt6Widgets.so.6(Qt_6)(64bit)
libc.so.6()(64bit)
libc.so.6(GLIBC_2.2.5)(64bit)
libc.so.6(GLIBC_2.34)(64bit)
libgcc_s.so.1()(64bit)
libgcc_s.so.1(GCC_3.0)(64bit)
libstdc++.so.6()(64bit)
libstdc++.so.6(CXXABI_1.3)(64bit)
libstdc++.so.6(CXXABI_1.3.9)(64bit)
libstdc++.so.6(GLIBCXX_3.4)(64bit)
pkgconfig
pkgconfig(Qt6Core)
pkgconfig(Qt6Gui)
pkgconfig(Qt6OpenGLWidgets)
pkgconfig(Qt6UiPlugin)
pkgconfig(Qt6Widgets)
pkgconfig(Qt6Xml)
qttools6-designer = 6.6.2
rpmlib(CompressedFileNames) <= 3.0.4-1
rpmlib(FileDigests) <= 4.6.0-1
rpmlib(PayloadFilesHavePrefix) <= 4.0-1
rpmlib(PayloadIsZstd) <= 5.4.18-1

Content of RPM :
/usr/include/qt6/QtDesigner
/usr/include/qt6/QtDesigner/6.6.2
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/abstractdialoggui_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/abstractintrospection_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/actioneditor_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/actionprovider_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/actionrepository_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/codedialog_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/connectionedit_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/csshighlighter_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/deviceprofile_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/dialoggui_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/extensionfactory_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/formbuilderextra_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/formlayoutmenu_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/formwindowbase_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/grid_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/gridpanel_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/htmlhighlighter_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/iconloader_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/iconselector_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/invisible_widget_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/layout_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/layoutinfo_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/metadatabase_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/morphmenu_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/newactiondialog_p.h
/usr/include/qt6/QtDesigner/6.6.2/QtDesigner/private/newformwidget_p.h
There is 204 files more in these RPM.