National Insurance Number omitted from Payslip until 08/31/2024

Hi, I have been employed by a company since July 2022 and paid tax and national insurance, while I was studying in uni. However, they didn't ask me for my national insurance number and they have omitted it for one year. I am from South Korea and wasn't asked to create National Insurance Number. I believe I am eligible for the tax return because I only worked 16 hrs in a week last year but I believe my tax record is not applied to my account due to this reason. I've got all the payslips received from my company. How can I update my tax record? Now I started a full-time job in the same company and created my National Insurance Number.

Hi,
Please see the link here, Income Tax: general enquiries
HMRC's digital assistant should be able to assist in claiming any possibe tax refund and tax code questions.
Thank you.