Answers for "capistrano NotImplementedError: OpenSSH keys only supported if ED25519 is available"

NotImplementedError: OpenSSH keys only supported if ED25519 is available net-ssh requires the following gems for ed25519 suppor

echo "add your ssh private key path"
ssh-add ~/.ssh/id_rsa

Gem::LoadError : "ed25519 is not part of the bundle. Add it to your Gemfile."

echo "add your private key path"
ssh-add ~/.ssh/id_rsa