To enable Web extension support in GNOME Web:

To enable Web extension support in GNOME Web:

To install GNOME Web/Epiphany (Internet browser client):
sudo dnf install epiphany

To install Dconf editor (A graphical tool for editing the dconf database):
sudo dnf install dconf-editor

To enable extension support in GNOME Web (Epiphany):
gsettings set org.gnome.Epiphany.web:/org/gnome/epiphany/web/ enable-webextensions true

or

1) Open Dconf Editor application
2) Click "I will be careful" if you face
3) Go to this path (org/gnome/epiphany/web)
4) Then scroll down and find enable-webextensions option
5) Turn on the option
6) Close all the applications and then restart or log out the system

To download any particular extension:
1) Go to this Firefox website: https://addons.mozilla.org/en-US/firefox/extensions/
2) Search your favorite extension(s)
3) Choose any extension which you liked
4) Click "Download file" at the bottom of "Download Firefox and get the extension" button
5) Choose a best location and save the desired "xpi" based extension

To install any particular extension:
1) Click the hamburger menu/three line menu button at the top right corner
2) Select "Preferences" option or press "CTRL+," buttons
3) Click an extension option at top right corner in the preferences window
4) Click "Add new extension" button
5) Open up that desired "xpi" based extension
6) Enable that extension by toggling the extension option

To disable any extension:
1) Click the hamburger menu/three line menu button at the top right corner
2) Select "Preferences" option or press "CTRL+," buttons
3) Click an extension option at top right corner in the preferences window
4) Disable any extension which you wanted by toggling the extension option

To remove any extension:
1) Click the hamburger menu/three line menu button at the top right corner
2) Select "Preferences" option or press "CTRL+," buttons
3) Click an extension option at top right corner in the preferences window
4) Click on the name of the extension
5) Click on "Remove Extension" button remove an extension