Thank you so much for your response. I had been using this method to change the sizes, but to no avail. I saw little to no difference. I had thought perhaps there was something in the Activello theme that could help me with this task. But, if not, that’s okay.
It appears to me that it does work, the changes are just very subtle on my end. They also don’t take right away after regenerating as they do in the video. But, I did see changes after increasing the size dramatically, regenerating the images and leaving the site for an hour. Thank you for your help. It does work, just not as it does in the video. Have a nice day.