@BRENDY77 It sounds as though you have installed the normal Raspberry Pi OS on your SD card. You need to install the modified Raspbian Openflexure OS on the SD card instead.
First download the Raspbian Openflexure image from the openflexure web site at https://openflexure.org/software/raspbian-openflexure/.
With a copy of this on your computer you then open the Raspberry Pi Imager and in the choose OS you need to select the option to browse for the operating system image for the microscope that you have downloaded.
[ Edit: From your other thread, you actually need the operating system with the draft fixes that will enable the Sangaboard v0.5 prototype. Download that from the link in post 16 in this thread Sangaboard v0.5 now available - General - OpenFlexure Forum ]