How do you do that with this card?
This is the exact model
https://www.amazon.com/ASUS-2GB-Graphics-Cards-R7240-2GD3-L/dp/B00FW5B3ZO
Sorry... here's my specific graphics card today: ASUS 2GB Graphics Cards R7240-2GD3-L
Around $60 on Amazon
That is a small PC. Here is the PDF manual Looks like you have a PCI-e x16, so you got that going for you. It looks like the PSU is 220 watts. It does look to be a slightly funky shape, not like a normal mini-ITX, which really only go to 300 - 350 watts normally.
So the best thing to do is get a lower powered video card with the most up to date GPU. This ASUS R7 240 has reviews from people with 220w PSUs.