I have a laptop with an AMD Ryzen 7840U CPU, and I can use AMDGPU.jl. But I had to set one environmental variable:
export HSA_OVERRIDE_GFX_VERSION=11.0.2
Also have a look at: Support for RX6600XT (gfx1032,navi23)? · Issue #1698 · ROCm/ROCm · GitHub
List of officially supported GPUs: System requirements (Linux) — ROCm installation (Linux)
Again, some GPUs that are not officially supported also work.