The Dell you mentioned is a laptop, so no you can't install a dedicated graphics card, however you can buy an external GPU enclosure which allows you to use a desktop graphics card with your laptop. However, you can't use them at the same time unless you use them on separate monitors, but they won't 'together' on a game for example. Hope this helps!
If you want to know more about external graphics card enclosures, take a look here > https://www.howtogeek.com/295442/the-best-ways-to-connect-an-external-graphics-card-to-your-laptop/.