JS - Base64

OK QuickBase Smarty Pants, I need some serious help!  Here is my situation:

I have 3 fields:
1 - [URL] - (URL) Holds the URL for the media file I want to upload later
1 - [Formula] - (Formula text) Formula below to go to the internet & finds the Base64-encoding for the [URL] field and puts the Base64 value in the [Base64] field.
1 - [Base64] - (Text) Holds the Base64 value that will be used in my API to upload the media file into my QuickBase record.

I am using the following formula to take the [URL] field & put the Base64 code into the [Base64] field.  However, I am receiving a syntax error.  I have been looking over it and can not find anything wrong.  Could it be my field type or am I actually missing something in my formula?

var url = "https://raw.github.com/carlo/jquery-base64/master/jquery.base64.min.js";
$.getScript(url,function(){
  $("#_fid_6").on("blur",function(){
    $("#_fid_15").val($.base64.encode($("#_fid_6").val())
  });
});