flutter: How to use texture on Linux

I want to integrate OpenGL in Flutter project. I find Texture widget seems to be the answer but all the examples I found is for Android or iOS. I saw texture is supported in Linux engine too. But I can't find any tutorial. Let's say I've create a triangle in native OpenGL C++ code. Flutter texture widget requires a texture ID. How can I bind this ID to OpenGL context so I can display this triangle in texture widget?