[Solved] Easiest way is simply swipe your finger down for notifications.
Look for “Android System”. It may be showing :
Android System . Charging this device via USB^
Tap on this for More Options
You will see USB Preferences. Select “Use USB for”
“File transfer” option button and go back
The Windows File explorer will show “internal Shared Storage” sub-folder under your “OnePlus….” folder
Now you can browse all your phone folders. For Pictures Go to “DCIM” subfolder.