visual studio 2019 build error

[blessnhs]

Severity Code Description Project File Line Suppression State
Error CS0426 The type name 'JavaCameraFrame' does not exist in the type 'JavaCameraView' OpenCV.Binding C:\Users\nhs\Downloads\Xamarin.Android.OpenCV\src\OpenCV.Binding\obj\Debug\generated\src\OpenCV.Android.JavaCameraView.cs 38 Active
Error CS0426 The type name 'JavaCameraFrame' does not exist in the type 'JavaCameraView' OpenCV.Binding C:\Users\nhs\Downloads\Xamarin.Android.OpenCV\src\OpenCV.Binding\obj\Debug\generated\src\OpenCV.Android.JavaCameraView.cs 43 Active
Error CS0426 The type name 'JavaCameraFrame' does not exist in the type 'JavaCameraView' OpenCV.Binding C:\Users\nhs\Downloads\Xamarin.Android.OpenCV\src\OpenCV.Binding\obj\Debug\generated\src\OpenCV.Android.JavaCameraView.cs 48 Active

i try this error but
I couldn't solve it.
plz help me