Hi guys

I am a bit confused here, Just bought Dell Optiplex 7020 sff pc and was wondering if GPU upgrade is possible. I have searched for it via dell websites and fund support pages for Dell discrete gpu options. But there is no mention of PSU which is as standard 255W !? Both AMD cards have 40-50W power consumption. I just dont wanna burn or overheat this pc... at the end using integrated card vs AMD ? Watch videos, browsing casual web gaming for my daughter...

Can you please advice....