Install libsdl-mixer1.2 by entering the following commands in the terminal:
sudo apt update sudo apt install libsdl-mixer1.2
Mixer library for Simple DirectMedia Layer 1.2, libraries
SDL_mixer is a sample multi-channel audio mixer library. It supports any number of simultaneously playing channels of 16 bit stereo audio, plus a single channel of music, mixed by the popular FLAC, MikMod MOD, Timidity MIDI, Ogg Vorbis, and SMPEG MP3 libraries. . This package contains the shared library.