1.ubuntu sidebar bottom
Copy and paste–or type–the following command into the terminal window and press Enter. The launcher will immediately appear at the bottom of your screen, so you don’t have to reboot or log in and log out again.
gsettings set com.canonical.Unity.Launcher launcher-position Bottom
To move the launcher back to the left side of the screen again, run the following command instead:
gsettings set com.canonical.Unity.Launcher launcher-position Left
Option Two: Use Unity Tweak Tool
Unity Tweak Tool is a third-party application that allows you to quickly control this and many other hidden Unity desktop settings