Please transpose the pension you received in from the Netherlands (in pounds sterling) in the tax year 1 January 2022 to 31 December 2022 into the UK tax year 2022 to 2023.
There is no need to apportion months. We accept the 01/01 to 31/12 as the same as 06/04 to 05/04.
You will need to work out how many payments you received Jan to Dec eg. 12*£500.00 = £6000.00. Declare £6000.00 in your SA tax return.
You should use the Euro value and convert using the official exchange rates.
The official exchange rates can be found here - Exchange rates from HMRC in CSV and XML format