Can't add SSH key to command


I try to push code to the server via git ftp tool. But I can’t add key. I have already add ssh key to “Additional SSH Keys” and use command add_ssh_keys and fingerprints this key. BUT I DON’T know how to add this to command:
git ftp init -u “{user}" --key "~/.ssh/*.pem" "{sftp}${path_to_test}”
After --key I need to add this key in order to connect to my server and push code.

- add_ssh_keys:
- “*************************”

  - checkout

  - run:
      name: Deploy Test Branch
      command: |
        sudo apt-get update
        sudo apt-get -qq install git-ftp
        echo "Deploying project ..."
        echo $(git status)
        git ftp init -u "${user}" --key "~/.ssh/*.pem" "${sftp}${path_to_test}" -vv


Please SSH into a container and run the commands manually to see what error you are getting. This will also help you to troubleshoot the issue.

Pawan Bahuguna