Where’s your problem? Just buy it and get the key match cut by a locksmith. Result. In fact I might buy another spare myself.
Unfortunately I lost the red passive key few months ago and I ordered one from Ducati for 35euro. As soon as I received it they programmed it and all I had to do was to copy the metal part from the black active key. Finally I found the lost one and didn't copy the new. It could be used to start the engine though. Recently I lost the black active key!!! I ordered a new one from Ducati for 130euro and as soon as I received it I went to the dealer to program it. Then and all I had to do from my side was to copy the metal part from my red passive key. Finally I got a little in trouble since it was difficult to find a locksmith to cut it. One after the other they were refusing to copy it claiming that they do not take the responsibility if something goes wrong. At the very end I only managed to cut the second red passive key. The black key blade is somehow little bit shorter than the red key and the guy over there advised me to not take the chances to avoid an undesirable result. Note that he did copy it by the machine manually. The blade of the red key could go full in the machine like the red key in order to be cut equally. There are a kind of CNC machines for such cases where they put the new key to be cut and the relevant code for the corresponding model, i.e. multistrada 1200s 2015my etc. and you have a factory result. However data for my multi 2015 my have not been released yet. That's my input and sorry for the long story!!!
My wife lost the only key on an Audi and it was a nightmare to get another, passports, documents, ID and a couple of hundred pounds, and two weeks.
After leaving the key under the seat and setting off, luckily not loosing it in few miles but scared enough to do something, bought a pair of blank keys from eBay for £6 and took to local Timpson. The lad in the shop said the same as others, would not guarantee if work, but he had a go and voila!, worked perfectly for the tank and seat. No need to take the active key off the pocket anymore. And because he was a bike passionate as well, did not charge me! However I brought him a nice coffee and donuts later. https://drive.google.com/open?id=1Ia2Bzv5l3cUkhVjw4g5_vmM3uZBJOsCY
+1 I've left my bike overnight parked outside a hotel with the "real" key under the seat. OK, so the hotel was in Fuente De in the Picos so not really a problem
The dealer lost (misplaced) the red key when I purchased my 18 Multi 1260PP. Consequently, they offered me a second FOB with a blank blade in lieu of which I had a locksmith cut to match. I have great news to announce. You don't need to buy another Red key. Just get a second FOB. FOBs can be reprogrammed as a passive key as both of my FOBs will start the bike without a battery in them.
