I hope you are well today and thank you for your question.
You have to activate the Unyson plugin SEO extension then you can change it from page edit screen as shown in the attached screenshots.
Thank you. I have it activated and will update these descriptions. I should have been more clear I guess. What I am looking to change is the browser tab descriptions. So when I have my site open, and I hover my mouse over the browser tab, there is a description. I am not sure how I change that.