Make PPK to Pem using Mac terminal

sudo port install putty
or

brew install putty


This will also install puttygen. To get puttygen to output a .PEM file:
puttygen privatekey.ppk -O private-openssh -o privatekey.pem

Once you have the key, open a terminal window and:

ssh -i privatekey.pem user@my.server.com

The private key must have tight security settings otherwise SSH complains. Make sure only the user can read the key.

chmod go-rw privatekey.pem

Install NVM (Node Version Manager) on macOS with Homebrew

Step - 1:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
echo "# Homebrew\nexport PATH=/opt/homebrew/bin:\$PATH" >> .bash_profile

source ~/.bash_profile

or

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

echo "# Homebrew\nexport PATH=/opt/homebrew/bin:\$PATH" >> .zshrc
source ~/.zshrc

Step - 1:

brew update
brew install nvm
mkdir ~/.nvm

echo "export NVM_DIR=~/.nvm\nsource \$(brew --prefix nvm)/nvm.sh" >> .bash_profile
source ~/.bash_profile
or
echo "export NVM_DIR=~/.nvm\nsource \$(brew --prefix nvm)/nvm.sh" >> .zshrc
source ~/.zshrc

nvm install 12.13.0
nvm install --lts

Install Telnet on MacOS using Homebrew

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

brew install telnet