Am doing my first deployment ever following this article from digital ocean

but its not been an easy one as i expected it to be. Actually when running the command mix edeliver build release i encounter this error that i have come to hate literally

ssh_askpass: exec(/usr/bin/ssh-askpass): No such file or directory
Permission denied, please try again.
ssh_askpass: exec(/usr/bin/ssh-askpass): No such file or directory
Permission denied, please try again.
ssh_askpass: exec(/usr/bin/ssh-askpass): No such file or directory
Permission denied (publickey,password).

A remote command failed on:

  mullah@example.com

Output of the command is shown above and the command executed
on that host is printed below for debugging purposes:

FAILED with exit status 255:

    current_shell="$0" || :
    [ -z "$current_shell" ] && current_shell="$SHELL"
    case "$current_shell" in
      (*bash*) echo 'bash is installed and the default shell' > /dev/null ;;
      (*zsh*)  echo  'zsh is installed and the default shell' > /dev/null ;;
      (*)
       echo
       echo "You are using an unsupported shell: '$current_shell'"
       echo "edeliver requires either bash or zsh to be installed"
       echo "and the default shell for the build user 'mullah'"
       echo "on your build host: 'example.com'."
       exit 1
       ;;
    esac
    set -e
    if [ ! -d /home/mullah/app_build ]
    then
      mkdir -p /home/mullah/app_build
      cd /home/mullah/app_build
      git init > /dev/null
      git config receive.denyCurrentBranch ignore
    else
      cd /home/mullah/app_build
      git config receive.denyCurrentBranch ignore
    fi

Will really appreciate any kind of assistance to solve this.
Thanks