Intuit just clarified that the Gain/Loss csv is no longer supported. To enter transactions from arbitrary sources use instead the Universal Template csv. (Can’t post the links here). Intuit articles:
How do I upload a CSV file of my crypto transactions?
How do I create a CSV file for an unsupported crypto source?
Will Koinly support exporting this template already filled this season, as this the new way to feed transactions to TuboTax as of now?
Having the same problem here as well. Quite disappointing that the integration with TurboTax is advertised at the Home Page of Koinly and no test was done before this tax season to find out that the 2025 mechanism no longer works.