See this TurboTax support FAQ for how to transfer the 2023 tax data file from a computer the 2024 online tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/transfer-last-year-return-turbotax-online/L279eUvY2_US_en_US?uid=m6wjpb7u