Installing Mono and Mono develop on Pi4 Raspbian buster

installtion.txt

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-raspbianbuster main" | sudo tee /etc/apt/sources.list.d/mono-official-stable.list
sudo apt update

sudo apt install mono-devel
sudo apt install mono-complete

sudo apt-get install -y mono-xbuild
sudo apt-get install gtk-sharp2

sudo apt install apt-transport-https dirmngr
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
echo "deb https://download.mono-project.com/repo/debian vs-raspbianstretch main" | sudo tee /etc/apt/sources.list.d/mono-official-vs.list
sudo apt update

Goto project options -> Run -> Default -> Disable Run on external console & Pause console output