Не получается добавить репозиторий

$ sudo add-apt-repository ppa:umang/indicator-stickynotes  
 Official releases of Indicator Stickynotes (https://launchpad.net/indicator-stickynotes).

To install Indicator Stickynotes, you will need to add this PPA to your system (instructions below) and install the `indicator-stickynotes` package. See the instructions below.

METHOD 1 (Command-line):

     sudo apt-add-repository ppa:umang/indicator-stickynotes
     sudo apt-get update && sudo apt-get install indicator-stickynotes

METHOD 2 (User interface):

     Step 1: Open "Software & Updates." Go to Other Software -> Add. Now type `ppa:umang/indicator-stickynotes` (without the `quotes`). Add the source and close the window. You will be asked to reload sources. Click "Reload".
     Step 2: Open the Ubuntu Software Center, search for Indicator Stickynotes, and install.
 More info: https://launchpad.net/~umang/+archive/ubuntu/indicator-stickynotes
Press [ENTER] to continue or ctrl-c to cancel adding it

gpg: создан щит с ключами '/tmp/tmpsx13u915/pubring.gpg'
gpg: /tmp/tmpsx13u915/trustdb.gpg: создана таблица доверия
gpg: ключ 799A5FD5D1C5997F: импортирован открытый ключ "Launchpad Pynagram"
gpg: Всего обработано: 1
gpg:                  импортировано: 1
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
gpg: не найдено данных формата OpenPGP.
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python3.9/threading.py", line 954, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.9/threading.py", line 892, in run
    self._target(*self._args, **self._kwargs)
  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 688, in addkey_func
    func(**kwargs)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 386, in add_key
    return apsk.add_ppa_signing_key()
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 273, in add_ppa_signing_key
    cleanup(tmp_keyring_dir)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 234, in cleanup
    shutil.rmtree(tmp_keyring_dir)
  File "/usr/lib/python3.9/shutil.py", line 718, in rmtree
    _rmtree_safe_fd(fd, path, onerror)
  File "/usr/lib/python3.9/shutil.py", line 675, in _rmtree_safe_fd
    onerror(os.unlink, fullname, sys.exc_info())
  File "/usr/lib/python3.9/shutil.py", line 673, in _rmtree_safe_fd
    os.unlink(entry.name, dir_fd=topfd)
FileNotFoundError: [Errno 2] Нет такого файла или каталога: 'S.gpg-agent.browser'

$key='<PUBLIC KEY>'