PDF Embedder plugin upload not open

I have the PDF Embedder installed and activated on my WP Dashboard. I want to use the embedded upload as my entire post, and have it be open for viewers to read directly. When I upload a .pdf file from my iMac, insert it in the post and publish it, and then try to read the text on my website by pressing the text name on the address bar on the website. But when I do, I get a screen with the message “404, Page not found.”
There is a button labeled “Search”; when I press it, I get a new screen with “Read More” (and an arrow) on it. I press that, and get a new page with the text title on it, but I can’t open the text.
I want the text to be open when it gets uploaded and published so that any viewer can read it. As I recall, that is what happened a few days ago when I first installed the plugin, so it seems possible to do. What’s going wrong now?