What makes you think you'd be able to installa graphics card in that laptop?
First of all, do you have enough power and a connector somewhere on the motherbaord? Secondly, can you even open that laptop to install components and thirdly, Lenove is well-known for not allowing installation of 3rd party components such as graphics cards, WiFi cards and such that has not been validated (and doesn't have a signature that the BIOS recognize).