How to use the photography function on htcg8 mobile phone? I've tried for a long time, but I can only take photos, not videos? Please give some expert guidance.

Open the camera. There is a small arrow on the top edge of the window. Click the small arrow and drag it down. You will see the photos and videos. Click on the video and pull the small window back to the edge. At this point it becomes a video recorder. To change the camera, do the same thing. Click the small arrow and pull it down. Click the photo to change it back to the camera.