Ubuntu – Why does the dock appear on the left when the screen is locked

If you don't like to run command then open dconf-editor( by simply click show applications icon and search dconf) then go to

org > gnome > shell > extensions > dash-to-dock

and search for the show-apps-at-top and make it on

See screenshot for your reference:

Run the following:

cd /usr/share/gnome-shell/extensions/
sudo mv ubuntu-dock@ubuntu.com{,.bak}

Press ALT + F2 and type r in the input.

In case if you need to undo:

cd /usr/share/gnome-shell/extensions/
sudo mv ubuntu-dock@ubuntu.com{.bak,}