PDF name is always "render" can we change it?

Hi, I have everything set up and all works great, but the files are always called "render" and when you want to save the file name is "render" too, how can I change the file name?
And I don't mean "attachmentName" I am talking about the pdf file name that is open in a new tab, I want it to say "David's CV File", but they are all "render" is there a parameter to change that?