setting up parrot on a seprate disk

when setting up and installing parrot you are given a “install Parrot” file on your desktop. im running parrot off my external usb stick and want to set up parrot on my internal drive. how do i get the “install parrot” file to recognize that i want to set it up on the internal one instead of the external drive? (i dont have enough storage on my main usb but i have enough on my internal drive)