Are you asking how to transfer 2023 to 2024 when you begin your new 2024 return? You must do that transfer at the very beginning before you enter any 2024 information.
How to transfer last year’s 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=m6ayqk1s