See this help page below which refers to process for filing prior year 8606, if it didn't affect prior year tax you just need to mail the form not amend your 2023 return. When you do 2024 tax you'll need to provide the 2023 basis during the interviews, as it obviously wouldn't carry over.
the $425 will be taxable, form 8606 for 2024 will calculate the taxable portion of the conversion.
https://ttlc.intuit.com/turbotax-support/en-us/help-article/retirement-benefits/enter-backdoor-roth-...
