How do you deal with Grayscale GBTC distributions that occured in June, 2024 on TurboTax?my 1099B from Schwab shows them as proceeds w/o providing cost basis.

SInce no cost basis was provided, TurboTax treated them as gains, but Grayscale says to treat the distributions as non tax event (no gain no loss), how do I deal with that on TurboTax