How to start a steam game on dGPU?

[Hellwarson]

So I just installed LM 20.2 (Cinnamon) and I have a slight problem.

I am on a laptop and would like to us iGPU for most time and only use Nvidia when needed, i.e. games etc. I installed the drivers and choosed On-demand and it works great but it doesn't select nvidia for some games but it does for other.

I like to use desktop icons but it doesn't give me a choice to select NVIDIA GPU and they don't show up anywhere else.

What do I have to do to force it to start games with dGPU? My other alternative is to always use the Nvidia card but what are the drawbacks of that?

EDIT: It seems like the only game I play that is not using the dedicated GPU is Terraria. Ark and LOTRO works fine.

[DanielPe]

To make a game run using the discrete GPU, use these simple steps:
Select a game - that you want to run using your discrete Nvidia card - from the Library page of the Steam client, right-click, and select Properties.
Click the SET LAUNCH OPTIONS
Save your changes.