Normally, when you use the train function, it should open up the Reinforcement Learning Episode Manager. This tool allows you to see how the training is going. On the Episode Manager's chart, you can see the reward received for each training episode (EpisodeReward) and also the average reward value that's been calculated over a series of episodes (AverageReward).
Read more about the Episode Manager here: https://www.mathworks.com/help/reinforcement-learning/ug/train-reinforcement-learning-agents.html#:~:text=and%20GPUs.-,Episode%20Manager,-By%20default%2C%20calling
Hope this helps.
