Prevent app from auto-launching upon system startup

I have downloaded and installed Sunflower remote control client for macOS. Every time I boot up my Mac, the software launches automatically.

I do not want the app to launch on startup. I looked up under System Preferences → Users & Groups → Login Items, but couldn't find an entry for the app.

How can I prevent the app from launching automatically upon system startup?

Solution 1:

Many apps have a checkbox or a pulldown menu in the preferences panes where you can instruct it to launch on login. Start your app and under the first menu item select preferences (NOT system preferences under the Apple menu item). Look thru all the preferences panels and one should have a designator switch to launch at login.