nexxPLAY offers also an official Flutter Plugin for Integration in Flutter Projects (on android).
All Player Funcitonality of the native android SDK are also supported via Flutter, most important that is:
Environment and Configuration Settings
SDK Methods and Options
You can find the official Plugin in its latest Version here:
nexxplay | Flutter Package
3Q nexx also provides a sample Application based on the Flutter Package with additional Documentation here:
GitHub - 3qnexx/nexxPLAY-Flutter
We strongly recommend, that especially for more complicated Cases with many SDK Methods, Picture-in-Picture and Fullscreen, you take a look at the example main.dart File, as given in the Sample Project.