Go to Settings > Prep & Ship > General and update "Minimum Expiration date" . It will set the minimum expiration date to the same and will not allow to enter a date before that.
As an example, on Feb 08, 2024, Minimum expiration date was set to 90 days and hence cannot select a date before May 8th 2024 (Feb 8th + 90 day = May 8th) for an item in the batch, shipment or PO etc.