Moved to the US in August, when to inform HMRC

I am seeking advice on how I notify HMRC that I have moved from the UK to the US, where I commenced work in the latter on 26th August 2024. I have filed a self-assessment for the last 8 years in the UK. Looking through the advice page [1] it would appear that I need to fill in the S109 form and the self-assessment also, but not online. However, I am confused by the sequencing of sending these forms: 1. Do I include the S109 form with the self-assessment for the April 2023 -- March 2024 tax year? or; 2. Do I Include the S109 form with the self-assessment for the April 2024 -- March 2025 tax year? Thanks [1] https://www.gov.uk/tax-right-retire-abroad-return-to-uk

Hi,
If you left the UK in August 2024 that will be for the 2024/25 tax year and if non resident from then the SA109 will be for 2024/25. 
Thank you.