I got a letter for Self Assesment and UTR, but don't have option to do it in my PTA

Hi, I got a letter from HMRC indicating I should complete a Self Assesment for 2022-23 period, and another with a UTR number, but for a NI number that doesn't correspond with mine. When I log in into my Personal Tax Account in gov.uk, I don't see the option to fill the Self Assesment, but instead a message saying: "You paid the right amount of tax for 6 April 2022 to 5 April 2023. Because HMRC have no record of you being employed from 6 April 2022 to 5 April 2023, you have no more Income Tax to pay for that year." How should I proceed then to fill the Self Assesment? Thanks, Carlos.

Hi CarlosBR,
Your UTR will be linked to a temporary national insurance number.
If you contact HMRC we can update this to link to your correct national insurance.
Once updated the Self Assessment option will then show online
Self Assessment: general enquiries
Thank you.