You need vkd3d-proton installed in your bottle in order to use dx12.
info: D3D11CoreCreateDevice: Probing 49664
err: D3D11CoreCreateDevice: Requested feature level not supported
info: D3D11CoreCreateDevice: Probing D3D_FEATURE_LEVEL_12_1
info: D3D11CoreCreateDevice: Using feature level D3D_FEATURE_LEVEL_12_1
info: Device properties:
info: Device name: : AMD RADV POLARIS10
info: Driver version : 22.1.7