To use your page your customers, students, vendors, etc need to navigate either directly or via a link to your upload page URL for example https://filerequestpro.com/up/demo
An alternative is to directly embed your page into your website displaying a seamless experience for your customers.
Feel free to upload a file if you wish so.
Once at your page user have two options, either she drops the files into the upload page or she can click to the link to open a file explorer windows where she can choose which files she would like to upload.
When the upload is complete, you can either redirect the user to a new page in your site or show a custom success message