Sometimes the 'Suggest a Title' feature is on the library's main page (not on the Digital Media page).
Mine even allows one to select the format (book, ebook, audio book, etc.) and further notes...
"Thanks for suggesting an addition to our collection; we will forward it to our Collection Development Committee for consideration. Please remember that items must fit within our Materials Selection Policy and must be available in order to be added to our collection. If the item is added, you may use our Internet catalog to place it on hold and choose your pick-up location from any of our branches.
You must have an email software application on your computer to use this form. You may also visit any one of our branches to make a suggestion."