GNOME project has an entire website dedicated to extensions.
Open any web browser in your system and navigate to the following address: GNOME Shell Extensions Website
When you visit the GNOME Shell Extensions website, a message similar to the following will be shown:
To control GNOME Shell extensions using this site you must install GNOME Shell integration that consists of two parts: browser extension and native host messaging application.
NOTE: Click the Click here to install browser extension.
NOTE: An error may be seen informing the native host connector is missing.
sudo apt install chrome-gnome-shell
Simply click on the suggested add-on link in the web browser.
NOTE: A recommendation is to sort the extensions by your GNOME Shell version.
NOTE: Extensions can also be installed them from the link below:
You can see all your installed extensions on the website under installed extensions section.
NOTE: One major advantage of using the GNOME Extensions website is that you can see if there is an update available for an extension.