A laptop with NVIDIA Optimus technology has a built-in Intel GPU on which the laptop screen is always attached, and an NVIDIA discrete GPU.
This combination tries to normally use the simpler Intel GPU (which is onboard of your CPU) to save battery, and only switch to the Nvidia GPU when needed. Depending on your laptop brand/model there can be a switch to set this. For instance my laptop has some vendor software running in the tray where I can switch to Hybrid (Intel) or Discrete (Nvidia), which will then require a reboot. There’s often also a setting in the BIOS where you can select which one to use. (quote from R Burns)
Further there can be a setting in your Nvidia control panel where you can select for which application to use which GPU.
TouchDesigner usually will be doing all the processing with the Nvidia on a properly configured Nvidia drivers by default, you can confirm this by watching the task manager GPU graph. However, the Monitors DAT will still report Intel for the built-in display on most of these laptops because their displays are directly wired to the Intel GPU. So, even if the Nvidia GPU does the ‘work’, it then sends the final image through the Intel GPU to get to your built-in display, thus the Monitors DAT will continue to show Intel GPU for that display. But it should not get in your way in reality.