Не работает((((((((

dimas@dimas-PC ~ $ sudo apt install software-properties-common 
[sudo] password for dimas: 
Reading package lists... Done
Building dependency tree 
Reading state information... Done
software-properties-common is already the newest version (0.96.20.2-1).
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
dimas@dimas-PC ~ $ sudo apt-add-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: keybox '/tmp/tmpgzmo9zz7/pubring.gpg' created
gpg: failed to start the dirmngr '/usr/bin/dirmngr': No such file or directory
gpg: connecting dirmngr at '/tmp/tmpgzmo9zz7/S.dirmngr' failed: No such file or directory
gpg: keyserver receive failed: No dirmngr
dimas@dimas-PC ~ $ sudo apt update
Get:2 http://repository.spotify.com stable InRelease [3 302 B] 
Hit:3 http://ftp.fau.de/deepin unstable InRelease 
Ign:1 http://ppa.launchpad.net/umang/indicator-stickynotes/ubuntu artful InRelease 
Get:5 http://repository.spotify.com stable/non-free i386 Packages [1 136 B]
Err:4 http://ppa.launchpad.net/umang/indicator-stickynotes/ubuntu artful Release
 410 Gone
Get:6 http://repository.spotify.com stable/non-free amd64 Packages [1 588 B]
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/umang/indicator-stickynotes/ubuntu artful Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
dimas@dimas-PC ~ $ sudo apt-get install indicator-stickynotes
Reading package lists... Done
Building dependency tree 
Reading state information... Done
E: Unable to locate package indicator-stickynotes
dimas@dimas-PC ~ $