The key creation is a single step process (if you do not have it already):

1) Check if the key is already created:

ls -a ~/.ssh

2) If the directory is empty, create a new key:

ssh-keygen

Answer the questions. You do not need a passphrase although you can add it if you feel slightly paranoid.

3) Copy the key to your clipboard and send it to Sree:

cat ~/.ssh/id_rsa.pub

Add your key to your repository for authentication