Neural network predictive controller for MIMO system

Hello, I want to use the neural network predictive controller for MIMO system.

Examples of SISO systems are shown in documents.

However, I can not understand that how to use the controller for MIMO system.

I want to apply for the system with three-input and three-output.

[Yeon Kyu Kwak]

I also require it to be able to handle combination of three inputs -> three outputs. Were you able to find any solutions to this?