How to implement Q-Learning agent to custom reinforcement learning environment.

I want to create custom environment and Q-learning agent for my problem, I read documentation find a good detail about custom environment but for Q-learning agent documentation is bit confusing, I'm using first time this toolbox, any good example or any thing that can helpful is appreciated.

https://www.mathworks.com/help/reinforcement-learning/ug/create-custom-reinforcement-learning-environment-in-matlab.html

This is good for RL custom environement.