A5 Fax app is LEX ready and you do not need to create any custom VisualForce pages. 

 

What looks different in LEX:

  1. The page layout in LEX will look different in LEX verse Classic.
  2. Only thing that you should do different from this article when adding the “Send Fax” button with the URL you create to page layout. Rather than finding “Send Fax” in buttons section in the Page Layout Editor in Classic, you will find this button in the Mobile & Lightning Actions section.
  3. See example photo below of Sent Fax related list showing Send Fax button from drop down on Opportunity page layout in LEX.

 

Lightning Restrictions:

  1. The only feature restricted with A5 Fax app in LEX is our automation feature that comes with installed package is triggered by ATTACHMENT type and not FILES type.
  2. You can still fax with Files and setup another automation method if you would like. See this article for more detail on fax formats and this article for other automation options to work with Files.