Tweak tool let's you to customise the appearance of your system.
Installing Tweak tool in Ubuntu is simple
All you have to do is, Run these command in Ubuntu Terminal
Press Ctrl + Alt + T to open the Terminal
To Update the Repository run
sudo apt update
Now, Install gnome tweak tool.
sudo apt install gnome-tweak-tool
That's it. Installation is complete.
You can open Activities to launch Tweaks or Run the below command to launch it from the terminal.