When you activate your camera, do you appear in silhouette? Cease testifying anonymously.
When you turn on your camera and are backlit, you appear dark. It is possible to adjust a parameter so that your interlocutors can see you clearly.
To do this, go to the Teams settings (the 3 dots, then Settings).
In the Devices section, scroll down to Video settings. Then check Adjust brightness.
Your interlocutors will see you better. This setting is also present in the meeting options.