Interest gain from Hong Kong for tax years 2023-2024

Hi, I and wife gained some interest from bank and also Hong Kong government issued bond in tax years 2023-2024. We have done the check if you need to tax return for self assessment and the results are we do not need to apply UTR and do self assessment. But I know foreign interest need to be declared, I had declared by using Add missing investment income in check your income tax website and submitted. I would like know if it is a correct way to declare my foreign interest or I need to do it by self assessment? If I need to do in self assessment(we had just applied for the UTR number), what should I do in next step? And will the interest being doubled taxed? Last question, if declared in Add missing investment income has no problem, but I used 2024 Exchange rates from HMRC instead of 2023 Exchange rates from HMRC to calculate the foreign interest in GBP and submitted, how can I fix it? Thanks!

Hi,
Receipt of foreign interest is a Self Assessment criteria, and you will need to complete a tax return to delcare this. 
Thank you.