iPhone 10s - No Lightning to 3.5 mm headphone jack adapter in box

I purchased 2 iPhone 10s' a couple of months ago. Just recently I had an occasion where I wanted to plug some high-quality headphones into my phone. Day to day I use Bluetooth. So I went to the original packaging to find the adapter that I thought was included. I found their basic headphones, a charging cable and the charging adapter. Being my 5th or 6th generation iPhone, I probably have a dozen or more of the later.

What I don't find was the headphone adapter. I called apple to find that it was a purchasable option. For $1,150 I was totally astounded that this devoice was not included.