Can someone help me. My husband passed away on 12/22/2023, which meant I filed jointly. This form will not accept a date earlier than 1/2024. What do I do?

Very sorry for your loss.   Bu what are you trying to do?   The current online software is only for 2024 returns.  If you are trying to use online to prepare your 2023 joint return, that is a mistake.  You cannot use online for 2023.   Please explain what you are doing and we will help.