Plugin to retrieve random file from folder

I downloaded Scott Reilly’s Random File v1.6 plugin “https://coffee2code.com/wp-plugins/random-file/” in the hopes it would randomly retrieve one of the more than 3,400 very small text files I have stored in directory https://localhost/writerspark/blog/exercises but can’t figure out how to get it to work. I left a message for him, but not sure how lonk or if he’ll respond, as this has been around a while.

Anyone using this who might know how to set the upper limit for the random selection and how exactly to code it to look in a particular directory and display a random file in that directory. Not looking to set up any arrays with more than 3,500 links or anything like that.

Thanks,

Bill