Plasma and utilisation of Apper

Hello,
I have installed Apper on Debian 12 Plasma up to date.
Every time I want to do an uninstall/install, I get this message:

You have failed to provide proper authentication.
Please check any password or account settings.

Nowhere does the password box appear. So I can’t enter it.
When I click on the launcher and terminal and enter apper, both open, but I can’t install any software because it keeps giving me the error message:

You have failed to provide proper authentication.
Please check any password or account settings.

From the terminal via sudo the software won’t open:

sudo apper
[sudo] Password for sul :
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
kf.dbusaddons: DBus session bus not found. To circumvent this problem try the following command (with bash):
    export $(dbus-launch)

Through the terminal without sudo the software opens, but I can’t install anything because of the error :

apper
QCommandLineParser: already having an option named "h"
QCommandLineParser: already having an option named "help-all"
QCommandLineParser: already having an option named "v"
QCommandLineParser: option not defined: "install-provide-file"
kf.kwidgetsaddons: Invalid framesize.
kf.kwidgetsaddons: Invalid framesize.
apper:
apper:
apper: PackageKit::Transaction::RoleSearchGroup ""
void PackageModel::clear()
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
void PackageModel::finished() PackageKit::Transaction(0x5568414f43d0) PackageKit::Transaction(0x5568414f43d0)
apper: QModelIndex(507,0,0x0,PackageModel(0x55684126af90))
apper: appId "org.kde.kmahjongg.desktop" m_package "kmahjongg;4:22.12.3-1;amd64;debian-stable-main"
apper: current thumbnail QUrl("https://appstream.debian.org/media/bookworm/org/kde/kmahjongg.desktop/146847509864ec051c70ba3d8364474a/screenshots/image-1_224x116.png")
apper:
apper: New transaction
apper: transaction running
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
apper: QMap(("description", QVariant(QString, "KMahjongg is a solitaire game where the player removes matching Mahjongg tiles to clear the board.  A variety of tile layouts are included, as well as an editor to create new layouts.\n\nThis package is part of the KDE games module."))("group", QVariant(uint, 11))("license", QVariant(QString, "unknown"))("package-id", QVariant(QString, "kmahjongg;4:22.12.3-1;amd64;debian-stable-main"))("size", QVariant(qulonglong, 4208760))("summary", QVariant(QString, "mahjongg solitaire game"))("url", QVariant(QString, "https://games.kde.org/")))
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
apper:
apper: PackageKit::Transaction::RoleGetDetails PackageKit::Transaction::RoleGetDetails
apper.lib: PackageKit::Transaction::StatusUnknown PackageKit::Transaction::RoleInstallPackages
kf.kwidgetsaddons: Invalid pixmap specified.
kf.kwidgetsaddons: Invalid pixmap specified.
kf.kwidgetsaddons: Invalid pixmap specified.
kf.kwidgetsaddons: Invalid pixmap specified.
apper.lib: PackageKit::Transaction::ExitSuccess PackageKit::Transaction::RoleInstallPackages
void PackageModel::finished() QObject(0x0) QObject(0x0)
kf.kwidgetsaddons: Invalid pixmap specified.
apper.lib: errorCode:  PackageKit::Transaction::ErrorNotAuthorized "Failed to obtain authentication."
kf.kwidgetsaddons: Invalid pixmap specified.
apper.lib: PackageKit::Transaction::ExitFailed PackageKit::Transaction::RoleInstallPackages
apper.lib: 1
void PackageModel::clear()
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
kf.kwidgetsaddons: No frame loaded
void PackageModel::finished() PackageKit::Transaction(0x556842bbe050) PackageKit::Transaction(0x556842bbe050)

It asks me to install dependencies after selecting the software to install, I validate and it gives me the above error.
I installed apper with discover.

I placed this order without success: apt install --reinstall --install-recommends apper

I installed Apper because Muon no longer works with Debian 12.
Any ideas?
Thanks for your help.

It sounds like your system’s PolKit rules have gotten messed up somehow.

But Apper isn’t a KDE app; I think you need to ask the Debian folks for help here. This issue doesn’t look related to anything KDE has any control over.

yes it is. See https://invent.kde.org/system/apper

Thank’s for your answers.

Fascinating. I think GitLab’s search UI failed me:

Is it marked as unmaintained or something?

There is a related bug on this:
https://bugs.kde.org/show_bug.cgi?id=471552
See the workaround at the bug report (basically, edit the application entry to have it run as root)

I’m having the same problem as the OP, also on Debian 12 with KDE Plasma.
You mentioned

sounds like your system’s PolKit rules have gotten messed up

and can you elaborate? How to check if this is indeed the case? How to solve it?

I tried the other solution mentioned here (running Apper as root) but that doesn’t work.