Plugin does not appear on the Dashboard Navigation Menu

I have the task of being the webmaster for a small nonprofit organization that is using a WP website. The site was originally designed by a professional web designer but he is no longer supporting the site.

My question is, the option for “plugin” does not appear on the navigation menu in the dashboard. I have started a personal site as a learning tool and I see the “plugin” option on the navigation menu on my personal site. The site is https://kairosfamilycounseling.com/ The theme is RT-THEME 17.