Install libphonon4qt5experimental4 by entering the following commands in the terminal:
sudo apt update sudo apt install libphonon4qt5experimental4
multimedia framework from KDE using Qt 5 - experimental library (internal)
Phonon is a Qt 5 multimedia API, which provides a task-oriented abstraction layer for capturing, mixing, processing, and playing audio and video content. . This package contains the Phonon-Experimental library, which might be needed by Phonon back-ends or other internal applications. Third-party applications should not depend on this library. Please read README.Debian before using this library.