Yes, absolutely. Listing your prior publication will increase trust in that you will be able to the same during your PhD studies. Writing and publishing is a skill that you will definitely need during this journey, and while it's possible that after 20 years you are out of practice, you still have the background that you can tap into. This, to me, is important.
A lot of students initially struggle with this, so providing evidence that you possess this skill and have experience will likely be a plus in the evaluation. In addition, you are likely competing with a lot of other applicants without this experience so this will potentially set you apart.
I agree with previous answers that you should be prepared to discuss your role in the
