Perhaps you want to run a certain command often, or have a program installed that for some reason wasn't added to the app drawer. Well, if you know the command to start it, that can be fixed easily.
You'll want to go to /home/phablet/.local/share/applications (image 1). Can't find it? Make sure you have show hidden files enabled. Here you'll see a lot of .desktop files - create a new one of the form name.desktop. Note that this is not the name you'll see in the app drawer, we'll specify that later.
Open the file with a text editor. I can recommend Seabass2 if you don't have one yet. The first line should be:
[Desktop Entry]
Then we need to define three values: Name, Exec and Icon. For example:
Name=Discord_Libertine
Exec=libertine-launch -i focal-3 "armcord"
Icon=/home/phablet/Downloads/Discord.png
Replace the values with what suits your usecase, of course. There are some more things you can specify if you want:
Terminal=false
Type=Application
Comment=Launch Armcord inside Libertine
And so on. These have, as far as I can tell, no effect.
And that's it! Save, refresh the app drawer by pulling down, and it should show up just fine.
The folder where you have to make the .desktop file:
An example file:
Discord_Libertine in the app drawer: