A few people have been scammed on the site, Only use paypal to pay for items for sale by other members. If they will not use paypal, its likely a scam NEVER SEND E-TRANSFERS OF ANY KIND.
Incompatible. The lids are different shapes as is the bodywork surrounding the lid. Search for "aerial" photos of the frunk lid on 2016 vs prior years. You will see they are different, particularly around the key hole.
You could try the SW-Motech “Quick Lock” system. They make a “Bolt on, Tank ring” that is intended to mount on a regular bike’s fuel filler cap. But you can just drill thru the “Frunk lid” to mount the lower ring. An upper ring mounts under the tank bag and “Locks Down” on the lower ring for a very secure mount. No straps or Magnets and the lid opens and closes just fine. (If you deceide you no longer want that mount, you could use epoxy to close the holes, or just buy a replacement lid.)