when you close (the red window button) the logitech g hub app, it hides the icon from the dock whilst keeping it running in the background.
This behaviour has been specially implemented in the Logitech G Hub app. It's not typical of apps in general, although I have come across a couple of others that do this as well.
Is It AppleScriptable ?
The first thing you need to determine is whether the Logitech G Hub application is scriptable, i.e. can it understand and be controlled by Apple events? Apple events are the inter-application messages that AppleScript uses to communicate with scriptable applications, and send instructions to perform a particular function.
The quickest discriminator in this regard is to use AppleScript to dispatch an instruction to the Logitech G Hub app telling it to close its windows.
To do this, create a new document in Script Editor, and make sure the Logitech G Hub application is up and running with a visible window on-screen.
Then type and execute the following code:
tell application "lghub" to close its windows
If the app is scriptable, then that's all the code you need, and your problem is solved. However, if it throws an error, it'll be because it won't be able to get the application's windows.
Otherwise, ...
In this eventuality, the application is not scriptable. So we'll need to resort to using System Events instead.
System Events is a multi-purpose, background-only (i.e. invisible), scriptable application that has a lot of feature sets. One of the most popular amongst novice scripters is its ability to hack the user interface and manipulate graphical on-screen elements of almost any application.
These elements include buttons, windows, scroll bars, text boxes, etc. It requires privileges to be granted in order to do this, so you'll get a few requests for authorisation upon attempting this the first time for any given application. It is a potential security issue once you grant authorisation, so bear this in mind considering what I've just described as being in the remit of System Events' capabilities, namely to assume control of any visual element on-screen.
Assuming you're fine with this...
Start with a blank document in Script Editor, and execute the following command to obtain the bundle identifier of the Logitech G Hub application:
get the id of application "lghub"
This will return a string along the lines of "com.logi.ghub" or something. It's another means by which we can reference the application instead of using its name ("lghub"). It's more robust to use the application id rather than its name in general, but sometimes it's necessary in System Events, which doesn't interface with the application object from above, but with a process (or application process) object that is something separate. Often, these are named the same as the application that spawns the process, but occasionally they're not. Bundle identifiers, however, are always identical.
Here's the code to close the window with System Events:
tell application "System Events" to tell (the first process ¬
whose bundle identifier is "com.logi.ghub") to tell ¬
the front window to if (exists) then tell attribute ¬
"AXCloseButton" to click its value
This targets the Logitech G Hub application process, which is a shell that contains everything needed for the application to run. This includes the physical UI elements, such as the window, which we first identify actually exists (to avoid throwing an error if it doesn't), and if so, we read off a reference to the red close button stored as one of the window's attributes. Once we have that reference, we can tell the button to behave as if we had clicked it, namely, to close the window.
Done.
To restore the window, you can do so like this:
tell application id "com.logi.ghub" to reopen
close window 1?