An alternative method is to change the reference type of your Endnote records from the “print” reference type (e.g., Journal Article, Book, and Book Section) to the electronic reference type: Electronic Journal Article, Electronic Book, and Electronic Book Section.
The Endnote MLA output style’s bibliography templates already include the URL field for the electronic references and seems to include the quotation marks around the Title field types so no modification is needed. However, if you find a set of quotation marks are missing from the Title field then just modify the bibliography template to include the quotation marks.