HMRC confirmation of no personal income tax owed

I moved from the UK to Slovenia in 2022, and in order to set up a business here, I must provide formal explicit confirmation from HMRC that I do not owe any income tax in the UK. The document must be legalized (apostille), and have a wet signature of an HMRC representative. I have managed to procure such a document in February '24 via an online chat with a very helpful HMRC customer service advisor, but the document has since lapsed due to being more than 60 days old. No agents I managed to speak with on the phone today managed to understand my request, or advise on how to proceed. How do I procure such a document / letter again from HMRC? All it needs to say is that I do not have any outstanding income tax due, and have a name / surname, plus signature of an HMRC employee.

Hi,
You will need to apply for this in writing and send it to HMRC PAYE & Self Assessment BX9 1AS.
Thank you.