wget https://10gbps-io.dl.sourceforge.net/project/firejail/firejail/firejail_0.9.48_1_amd64.deb

sudo apt install -y ~/firejail_0.9.48_1_amd64.deb

oder

sudo apt install firejail

firecfg --fix-sound
 sudo firecfg

firejail firefox