Undo retention

Hi Team,

We specifically want to ensure that we can retain sufficient undo to perform a Flashback Table/Flashback operation for at least 24 hours.

We would like Oracle Support's expertise on the following:

Please advise whether the current UNDO tablespace size is sufficient for our workload and Flashback requirement.
Based on the available database/server storage and our workload, please provide a recommended UNDO tablespace size and appropriate UNDO_RETENTION setting to achieve this requirement.
Please also advise whether there are any other database parameters, workload characteristics, or configuration considerations that need to be addressed to reliably retain undo for the required period.