I can think that WebcamCompat page is outdated or integrated webcam is not supported, in any case I cannot run after setting webcamd. Kamoso or Cheese can't find any device in FreeBSD/i386 12.1.
Code:
ugen4.2: <Syntek USB2.0> at usbus4, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (500mA)
bLength = 0x0012
bDescriptorType = 0x0001
bcdUSB = 0x0200
bDeviceClass = 0x0000 <Probed by interface class>
bDeviceSubClass = 0x0000
bDeviceProtocol = 0x0000
bMaxPacketSize0 = 0x0040
idVendor = 0x174f
idProduct = 0xa821
bcdDevice = 0x0005
iManufacturer = 0x0001 <Syntek>
iProduct = 0x0002 <USB2.0>
iSerialNumber = 0x000a <retrieving string failed>
bNumConfigurations = 0x0001