Which platform are you using?
If it’s Window you will need to go to your settings and then system - displays and see if your machine is able to detect the secondary monitor. If so there should be various options you can choose from on how to use the dual system. If you choose “extend display” you’ll be able to move the game to one screen and keep your work visible on the other.
It works very similar on Macs. Just check display in the system settings and make sure the correct display option is selected.
Both platforms will give you a preview before you need to commit to the new setting.
If your system can’t detect the monitor make sure it’s plugged into the correct port of your graphics card.
