I have already solved the problem with dell support. According to dell support, it will work. Thank you for replying and trying to help! 
Hello!I'm wondering if I can get an AMD R5-430 in my Optiplex 3020 SFF. There are a few things to consider, first of all, will it fit? I already checked that since it's a low-profile card. I'm pretty sure the card will fit into the slot in the computer. However, I'm also upgrading the CPU, according to Dell Support it will work. It's an i5-4590, the TDP for the CPU is 84 watts. And yes my main question is that will the power supply provide enough power for the AMD R5-430?
Optiplex 3020 SFF and AMD Radeon R5-430