Can't install GNOME shell extensions?

Question

New to Ubuntu. When I tried to get the GNOME user theme extension from the website, it would not load the button to install. So I tried the command in the terminal

sudo apt-get install gnome-shell-extensions-user-theme
and got the error message:
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package gnome-shell-extensions-user-theme

any help? Thanks! UPDATE: it's not the lack of an extension, I know I have it installed, and there is no pink banner. The page does not load any button for me to install (or the user reviews section.) The page does load on chromium (with the pink banner though, no extension) so I don't think its a network issue. Also, the 'duplicate'page is not my exact issue. And I tried this on firefox, which has the right extension on it by default.

Solution

You can install only official gnome extensions available in Ubuntu repo using sudo apt-get install gnome-shell-extensions.

To install other extensions you need Firefox browser. Visit https://extensions.gnome.org/ to install all the available extention.

If you see webpage like this

It means that you need to install GNOME 3 Integration plugin in your browser. Install it from here.

Once plugin added to your browser, you can install all the available extensions from https://extensions.gnome.org/.

Comments

[muru]

Which browser did you use? Is the Gnome integration plugin enabled?

[Pyrophorus]

Why not using Ubuntu Software Center ?

[xCvl]

@karel after step 2 it said "ERROR 404: Not Found."

[karel]

Here is the explanation of the steps. 1. Change directories to your Downloads directory. 2. Still in the Downloads directory, download your file. 3. Unpack the archive. It will create a new directory called gnome-shell-extensions-3.13.91 with the installation files in it. 4. Change directories to the new directory. 5.-8. These 4 steps install gnome-shell-extensi‌​ons. All the filenames and the names of the directories are case sensitive and have to match EXACTLY.

[xCvl]

@karel ok i got a little farther, now when I try to run "./autogen.sh" it says I need to install gnome-common from GNOME Git; which I tried to do by downloading a .tar.xz file from here (git.gnome.org/browse/gnome-common) but IDK what the next step is to download it. (and thank you for putting up with all this)

[karel]

The message you got was "You need to install gnome-common from GNOME Git (or from your OS vendor's package manager)". Well, gnome-common is in the Ubuntu Software Center, so it would be easier to just install that. The last line of the install script is looking for a file called gnome-autogen.sh which is included in gnome-common from the Ubuntu Software Center.

[xCvl]

Yeah I have the extension, and that's the problem. There is no pink banner, but also no button, and the user reviews section never loads. I tried it on chromium (no extension) and the page loads fine, but with the pink banner so I don't think its a network issue.