1. Open terminal on Mac

2.1. 

ssh USERNAME(e.g. djangoadmin)@IP ADDRESS(111.11.111.11)

2.2. type exit to log out

2.3. If you can't log in, try 

ssh-add ./.ssh/id_rsa_do
If no errors, below should be displayed. If below didn't display, Idk, good luck. 
Identity added: ./.ssh/id_rsa_do (DependsOnPeople@DependsOnPeoplenoMacBook-Air.local)

3. type below, to get in venv. 

source venv/bin/activate

4.1. go to your project directory, then pull your code from GitHub. 

cd pyapps
cd pfc_calc
git pull origin

4.2. You can check your directories by typing so. 

ls

5.1 migrate

python3 manage.py migrate

6.1 restart

sudo service gunicorn restart
sudo service nginx restart

Reference