Accessibility for Vision Impaired - How do I active the screen reader to test my ggplots?

Hello, I am trying to learn how my alt text for a ggplot sound sounds on the screen reader. I am using RStudio Server and R 4.0.3. I have changed my global options for accessbility. But I can't find the next step. Can someone point me to an easy to use video or resource? Currently the documentation is really cumbersome and I just can't figure it out. Thanks so much