CA doesn't allow for applying a refund generated by an Amended return.  The overpayment from the original that was applied should still be in place.  Your client will have to settle for a paper check.  You 'could' try having them send the check back when it arrives, with a note to 'apply to 2023'.   That has worked in the past (with the FTB & the IRS) but I'm not sure I trust them to not lose it in their system for a long, long, long  time....