Bootstrap-5

I am working on a Drupal 10 site with a Bootstrap 5 (Barrio) custom theme. I have some older followers who would find it easier to view the site if the type was larger. I want to provide a large-print option for them. Is there a way (such as a user-selectable option) to accomplish this through the theme?

It looks as if "Userway" is an option, but it is expensive and offers several features that I don't need.