You can´t see it there because it`s a plugin. You can only see it in:I have installed and reinstalled the plug in a number of times, but when I go to "components" and "main menu" it is not there!
Backend --> Extensions --> Plugin Manager
There you have to enable it.
To create correct code for the Phoca Gallery Plugin it`s helpfull to install the Phoca Gallery Button Plugin too.
https://www.phoca.cz/phocagallery-button
Kind regards,
Benno