Hi Haximus,
After the tax year 23/24 ends on the 5th of April 2024, the quiz (checklist) you've taken on Gov.uk will reset to query whether you need to complete a return for 23/24.
Complete the checklist then, and it should register you for Self Assessment.
Alternatively, contact us by webchat or phone here:
Self Assessment: general enquiries
So we can register you.
Thank you.