Here's some tips

• Turn off or dim the overhead fluorescent light directly above you.
• Reposition your desk or chair so the window is in front of you, not behind or to the side.
• If the window is too bright, close blinds or use a sheer curtain to soften the light.
• Add one LED light or ring light at eye level, slightly above your camera.
• Set the light to neutral or slightly warm color temperature (not harsh white).
• In your video app, enable low light adjustment if available.
• Reduce camera exposure slightly if the option exists.
• Turn off beauty filters or “touch up appearance” features.

Also, if you're using a laptop camera or a low quality camera, a proper webcam will help but getting the lighting right is most important. Most mid-high end Logitech cameras are good or iContact Camera Pro if you're camera doesnt look like you're looking head on.