Cose a program

[Darryould]

What steps should I follow to set up a task that will close a program?
The window is not visible when minimized, making it impossible for me to target and close it.

[Oleg]

Generally you can close the program when you close main window of the program.
Use Window Command action. It can process hidden windows too.

Another way - you can terminate process

[CharlesGutierrez]

While a script to force-close the program might seem like a solution, perhaps investigating why the window minimizes invisibly would be more beneficial long-term? It could be a software bug or a configuration issue. Fixing the root cause might prevent future problems and be a better approach than repeatedly ending the process. Something is making this not work as designed.