Hi James,
Once you have added the surplus allowance from the 3 previous years to your 2023/24 allowance, subtract it from your pension payment.  If you still have a positive number you have exceeded your tax free amount and will incur a pension savings tax charge.  
You are required to declare the pension savings tax charge in a self assessment tax return in box 10 of page Ai4 of SA101 (https://assets.publishing.service.gov.uk/media/660152aea6c0f7bb15ef9150/SA101_2024.pdf).  
You should discuss with your pension provider whether they are willing to pay the tax out of your pension pot.
If they are then you enter the amount in box 11.  
If you are submitting an online tax return, when tailoring your return, you select yes to the question "Are you liable to pension savings tax charges or have you received payments from overseas pension schemes?" on page 2 of 3.
Thank you.