There are two reasons: first, your network is too poor, so just change to a better network. Second, you didn't turn on the front camera, you just turned it on by flipping the icon. Let me share with you how to open it:

Software version: version? 3. 1 1.4.443。

Mobile phone model: oppoReno7.

Specific operation steps:

1. After entering Tencent Conference, click the video below.

2. Then click the flip icon above.

3. I can finally see myself in the camera.