i think you are using 'video_player 0.10.10' library.
It is useful to review the documentation on puv.dev.
If you are using IOS emulators, you should pay attention to this warning
'Warning: The video player is not functional on iOS simulators. An iOS
device must be used during development / testing. '
Add the following entry to your Info.plist file, located in /ios/Runner/Info.plist:
<Key> nsapptransportsecurity </ key>
<Dict>
<Key> nsallowsarbitraryloads </ key>
<True/>
</ Dict>
Android
Ensure the following permission is present in your Android Manifest file, located in /android/app/src/main/AndroidManifest.xml:
<uses-permission android: name = "android.permission.INTERNET" />