Dgpu and 3080 games box i need both enabled under windows 10 on my laptop

my razer 15 laptop has an 4k Oled display i wanted to upgrade my 2070 on board card so i bought a 3080 Games Box with Thunderbolt 3 when i plug it in the Razer 15 updates the NVidia to 3080 but switches off the 2070 i want both cards available is this possible or did i miss something in the manual it now means i have a 2070 completely useless and taking up space and power for no good reason.? any help fellow gamers.