The meeting says the camera is on, but your preview is black. A physical shutter can cover a functioning camera. An application can also select a virtual camera or an unused external device rather than the lens above your screen.
Inspect the camera area for a shutter or cover and check any hardware privacy switch described by the manufacturer. In the app, confirm the selected camera by name. If Windows provides a camera preview, compare its result with the meeting preview using the same device.
Do not dismantle the laptop or force a part that does not move easily. Identify the control intended by the manufacturer. A shutter that blocks light and a switch that disables the camera can produce different results.
Review camera permissions for the app or browser website. Permission can allow access while a closed shutter still blocks light. Conversely, an open lens does not grant an app permission. After changing one setting, repeat the preview test. When the picture returns, inspect the background before joining a real meeting; troubleshooting should not accidentally broadcast your room.