Hi, If you were made redundant in 23/24, you should receive your repayment when you file your 23/24 tax return. If it was in 24/25, you can use the P50 form, though some exceptions may apply - read more here:
Claim back Income Tax when you've stopped working (P50)
If you do receive a refund via the P50, please remember to declare this refunded amount in your 24/25 tax return.
Thank you.