Thanks in advance.

Are you on a desktop or laptop?
If you are on a laptop generally there are some brand/model specific ways of achieving what you want through the display settings unique to that laptop.
However if you are on desktop I recommend using the WinKey+P menu in order to move the display contents to another monitor before turning the monitor off. This will be the quickest and simplest way of doing things, but may not necessarily be what you are looking for (especially not automatic, but pretty good)

Other options are a bit more involved. Other options I would recommend is trying to utilize saved window states. This may only be beneficial if you use the same programs all the time and want to have say a 1 monitor setup of your programs when you only have one monitor on and a 2 monitor setup profile for when you have both monitors on.
This can be done with window position profiles within DesktopFusion. Right click on the system tray icon to find this option. You can even assign hotkeys for it.

I'm using a desktop PC. I'm currently using shortcut keys for switching between my two displays. Works reliable with Displayfusion.