The 9020 does have integrated graphics on the Intel CPU. Just make sure to download the driver here.
Hi..! I am a user of Dell OpltiPlex 9020.Suddenly my GPU (AMD) got hampered. That's why it does not show any display output.Is it possible to run my pc  without gpu from motherboard and get a display output?  Please Help me.. Thanks in advance 
Run an Optiplex without a GPU