Val

I was wondering if it is possible to claim Higher rate taxpayer Tax relief on pension contributions for previous Tax years via Self-assessment. I recently learned that it is possible to claim it up to 4 years back, but I am struggling to understand how to do it for tax years 21-22 and 22-23 as current tax return refers only to current tax year 23-24. Appreciate if you could let me know how to do it in current Tax return and how I can tell HMRC for which Tax year it is? Thank you