Hi Matt1455,
As you were resident in Italy for 2022/23 and if you do not need to complete a Self Assessment tax return, you will need to submit a completed P85, to confirm that you were not resident in the UK, but employed by a UK employer. You can see guidance here:
Get your Income Tax right if you're leaving the UK (P85)
If you are required to complete a Self Assessment tax return for 2022/23, then you would need to declare that you are not resident in the UK on SA109, declare your UK employment and tax deducted on SA102 and the amount of earnings not taxable in the UK on SA101 box 12.
Thank you.