Linux Tails（ターミナル）のNordVPNアプリのインストールに関する問題

インストールする必要がありますノースVPNLinuxに入る尾。指示に従ってターミナルウィンドウで通常のNordVPNを実行してください。https://nordvpn.com/download/linux/:

sudo apt-get install /home/amnesia/Desktop/nordvpn-release_1.0.0_all.deb

数秒後に続行することを確認すると、次のメッセージが表示されます。

*Get:1 /home/amnesia/Desktop/nordvpn-release_1.0.0_all.deb nordvpn-release all 1.0.0 [5,358 B]  
[INFO] Saving package changes  
Traceback (most recent call last):  
  File "/usr/lib/python3/dist-packages/apt/cache.py", line 194, in __getitem__
    return self._weakref[key]  
  File "/usr/lib/python3.5/weakref.py", line 137, in __getitem__  
    o = self.data[key]()  
KeyError: 'nordvpn-release'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apt/cache.py", line 198, in __getitem__  
    rawpkg = self._cache[key]
KeyError: 'nordvpn-release'


During handling of the above exception, another exception occurred:  

Traceback (most recent call last):  
  File "/usr/local/sbin/tails-additional-software", line 671, in <module>  
    apt_hook_pre()  
  File "/usr/local/sbin/tails-additional-software", line 459, in apt_hook_pre  
    if not apt_cache[package_name].is_installed:  
  File "/usr/lib/python3/dist-packages/apt/cache.py", line 200, in __getitem__  
    raise KeyError('The cache has no package named %r' % key)  
KeyError: "The cache has no package named 'nordvpn-release'"  
N: Download is performed unsandboxed as root as file  
 '/home/amnesia/Desktop/nordvpn-release_1.0.0_all.deb' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied)  
E: Sub-process /usr/local/sbin/tails-additional-software apt-pre returned an error code (1)  
E: Failure running script /usr/local/sbin/tails-additional-software apt-pre*  

この失敗をどのように克服できますか？