Once again - no screens

my problem is discussed multiple times, but still I cannot solve it.
I commit that I'm a FreeBSD newbie, but have experience in Linux (Gentoo).

startx fails, no matter what I do in installing components like drm-515-kmod, xf86-video-amdgpu, adding config files to .../xorg.conf.d/ or re-installing Xorg etc.

The log tells me:
(II) AMDGPU: Driver for AMD Radeon:
All GPUs supported by the amdgpu kernel driver
(--) Using syscons driver with X support (version 2.0)
(--) using VT number 9
(II) AMDGPU(0): [KMS] Kernel modesetting enabled.
(EE) AMDGPU(0): [drm] Failed to open DRM device for pci:0000:03:00.0: No such file or directory
(WW) VGA arbiter: cannot open kernel arbiter, no multi-card support
(EE) Screen 0 deleted because of no matching config section.
(II) UnloadModule: "amdgpu"
(EE) Device(s) detected, but none match those in the config file.
(EE)
Fatal server error:
(EE) no screens found
(EE)

pciconf shows:
vgapci0@pci0:3:0:0: class=0x030000 rev=0xcf hdr=0x00 vendor=0x1002 device=0x7480 subvendor=0x1043 subdevice=0x05f3
vendor = 'Advanced Micro Devices, Inc. [AMD/ATI]'
device = 'Navi 33 [Radeon RX 7700S/7600S/7600M XT]'
class = display
subclass = VGA