Evee and Workbench use Gpu when rendering but Cycles doesn't For some reason when I use the Cycles to render something it wont use my Gpu. I already changed it in my prefferences so I could use my graphics card. I have anA MD Ryzen 7 4800u graphics card and use Blender 2.83. But I also had this prolem with an older computer. What can I do tofix this problem?
As mentioned by @Eric Xue, the Ryzen 7 4800u is a CPU with only integrated graphics. Unless you have a dedicated graphics card, i.e nVidia Geforce RTX, or AMD Radeon, you cannot use the GPU render function because Blender does not render on integrated graphics.

Your GPU rendering selection is grayed out, signifying that you do not have a GPU or a  non-compatible GPU.

If you do have a compatible nVidia or AMD GPU, enable it in the Blender Preferences.