PayPal Donate Button in Menu

I am trying to figure out how to add a PayPal Donate button into the menu. I know how to generate the PayPal Donate button code or work with a short-code from a plugin. However, I cannot figure out how to get the button to show on the menu, right before the search. Ideally, the button would be reasonable in size to fit in well with the rest of the menu items.

Thanks in advance.