Chargeable Event from Life Insurance Surrender - do I need self assessment?

Help needed after a full morning bouncing around phone helplines! 1. Firstly, I'm unsure whether I need to file a self assessment tax form for 22/23 at all. I did a full surrender on a life insurance policy. I pay basic tax on my salary (£33214). The gain arising was £59,500, treated as having borne basic rate income tax. I'm therefore still under 100k for 22/23. I had the policy for 10 years, so after top slicing I don't think there's any additional income tax to pay on the gain? 2. When I fill out the "do I need to do a tax return", after the 10 qs it says no (as there's no question about life insurance gains - and i assume this isn't capital gains?). My PAYE page says everything is correct. 3. If I do need to declare this, is it "missing investment income", or "missing income from another source"? Should I do this via the PAYE summary page, or fill out a self assessment form? Thanks for your help everyone.

Hi

If your chargeable event gain is over £10000.00, then you meet the criteria for completing a self assessment tax return.  
Chargeable event gains, should be declared on SA101 page Ai1, boxes 4 and 5 please see Self Assessment: additional information (SA101)
Self assessment will calculate the top slicing relief for you.  
If you are completing your tax return online, when tailoring your return, select yes to "Did you receive any other UK income, for example, employment lump sums, share schemes, life insurance gains?" onpaqge 2 of 3.

Thank you