Bitcoin gift

I won a very small (under $20) amount of bitcoin in December 2020, I sold it about 2 weeks later.  I received a 1099 yesterday. Then I had to upgrade my TurboTax product - which I am not happy about.  I am being asked  for the amount paid for the Bitcoin.  I did not pay for it, so I have no idea what to put in.  Can I leave this blank since it was a gift.  Also, the amount of proceeds is double what I sold it for.  Thanks