I tried to install Startup Disk Creator using:
sudo apt-get install usb-creator-gtk
But it didn't appear in the dash.
What should I do?
"Click on the Ubuntu icon in the top left corner of the screen. After that type the letters of the program name and you should see them (the letters). And you should also see the selected items change. The more letters you type, the more specific selection, and after a few letters (and maybe some other characters (in this case the minus sign, '-') only one icon is left."
/sudodus - in the comments
Additonally you may pick (with the mouse) a visible icon and drag it into the Launcher, and it will sit there until you remove it.
If you cannot find it just install it running in terminal those commands (first two are optional, to update the repos, and upgrade what should be upgraded, but if you just want to make pendrive with installer, just skip to the third line.
sudo apt update sudo apt upgrade sudo apt install usb-creator-gtk
For me it worked, Ubuntu tutorials and forums stated that it is build in, from 18.04, but it's not if you have other flavor than "vanilla" Ubuntu, for example Budgie.
Then you may also start this from terminal:
if it doesn't appear in the dash then go to your package manager and search for startup, there you will find a package named "startup disk creator", right click on it and select mark for installation and then apply changes, after that close the package manager then search for startup disk creator, you will find it.