56 0 20

Last year I sold some of my product to a business customer.  The total sale was a little over $12k.  99% of my customers are private individuals.  This particular customer is an LLC.  Yesterday I received a 1099-NEC from this customer, which is NonEmployee Compensation. 

I've researched this for hours but still can't figure out why this customer sent this and what I am supposed to do with it.  In 11+ years of being in business, I have never been sent any kind of 1099 by a customer.  I was hoping there are some of you that perhaps are familiar with this and can give me some free tax advice.  Thanks.