i am new on Linux to and i can’t run this comment on linux CentOS
maybe this not for linux CentOS.
sudo apt install apt-transport-https dirmngr gnupg ca-certificates
sudo apt-key adv —keyserver hkp://keyserver.ubuntu.com:80 —recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
echo «deb https://download.mono-project.com/repo/debian stable-stretch main» | sudo tee /etc/apt/sources.list.d/mono-official-stable.list
sudo apt update