How to run scripts by selecting them from a dropdown menu

I am trying to create a shiny app where the user selects an r script file from a drop down menu, and the file has to show the output of respective r script that is selected in the dropdown ...

How to create dropdown ?and also how to code all that in server side of script ?

How would I be able to get a shiny app to show the r script file from a dropdown menu

Any help is appreciated