Recovering app icon on menu bar

Usually that option is in the preferences for the application. If it is an app that shows in the System Preferences/Settings, look to see if the option is there. Worst comes to worse, get the original installer to install it back.

Which app icon are you referring to? Sometimes this is controlled by the app itself, not the MacOS.

Have you checked this app's settings?

Which application? This is probably done in the application's settings.

When you say, "Menu Bar" do you really mean the Dock? If so, there are several ways to restore any app to the Dock.

Launch the app in Finder from the Applications folder. Then right click (or control click) its icon in the Dock and choose, Options > Keep in dock. Another way is to find the app in Finder and the Applications folder then drag the app from there to the dock.

With the application running, try pressing Command-Shift-O.

This appears in the ticktick page (I hope it is appropriate to post this screenshot from their website):

With so very little usable information to work from.

Perhaps if you provide some reliable , accurate, details / context will really help to pinpoint a possible solution.

We do not what to offer solutions you has already attempted.

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