sudo add-apt-repository ppa:linphone/release
sudo apt-get update
sudo apt-get install linphone

sudo add-apt-repository ppa:rayanayar/linphone
sudo apt-get update
sudo apt-get install linphone

linphone: symbol lookup error: /usr/lib/x86_64-linux-gnu/liblinphone.so.8: undefined symbol: belle_sip_stack_set_http_proxy_host

Could not find a support sound driver API

sudo apt-get install libasound2-dev

sudo su
sudo apt install flatpak
flatpak --user install --from https://linphone.org/flatpak/linphone.flatpakref

sudo su
sudo apt install flatpak
flatpak --user install --from https://linphone.org/flatpak/linphone.flatpakref

sudo su
sudo apt install flatpak
flatpak --user install --from https://linphone.org/flatpak/linphone.flatpakref