Exchange rates for foreign income

What exchange rate do I use for converting euros into pounds sterling for 2023-24 self assessment tax return?

Hi,
Under the terms of Self Assessment, we do not provide an official exchange rate and the onus is on the individual to use a just and reasonable exchange rate for each acquisition and disposal.
You are free to use any of the three rates HMRC provides, or you can use a rate obtained elsewhere, such as a newspaper or the London Stock Exchange.
For your convenience, there are exchange rates at:
The National Archives: Exchange rates from HMRC in CSV and XML format
For older rates at:
The National Archives: Foreign exchange rates and spot rates: 1 January 1989 to 31 March 2009
You are free to use any of the supplied rates or one of your own choosing
Thank you