What kind of debt was the 1099-C for? Did you declare Bankruptcy or Insolvency that year? Those two conditions cover most cases where a person can use 982 on a 2018 return, and You have to establish if either applies using your own records.
See https://www.irs.gov/forms-pubs/about-form-982
NB: Main home debt Was a reason to use 982 in prior years, but Not for 2018 returns ...
