Install brew, then:

brew update
brew install openssl
mkdir -p /usr/local/lib
ln -s /usr/local/opt/openssl/lib/libcrypto.1.0.0.dylib /usr/local/lib/
ln -s /usr/local/opt/openssl/lib/libssl.1.0.0.dylib /usr/local/lib/

Install .net Core SDK

Initialise some code:

mkdir hwapp
cd hwapp
dotnet new

Run the App

dotnet restore
dotnet run