Does anyone know if there is a way to make it so that the file drop box in apex only accepts powerpoint files? I can’t find any information on this.This is the kind of drop box I am talking about:
>Solution :
It depends on the plug-in that you use. For example, in my application, I am using this plugin and it has setting for accepted file types: 
If the plugin does not have a setting for the accepted file types, you may need to observe DOM structure of the element and reach to <input>tag of DOM by JQUERY and use accept attribute of HTML (https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/accept)