saving interests from child's bank account

I have transferred some money into my child's bank account and over 100 pounds interests was incurred. How can I report this to HMRC, which part of which form should I fill in the relevant information?

Hi,

If you already complete a tax return, this will be included within your savings income. If not, you can phone or write in with details.

Income Tax: general enquiries

Thank you.

This is for 22/23 tax return, I am going to complete the self assessment form. Which part of the form I should fill in the details of my child's account details?

Hi
You would enter this in the UK interest section.
You only enter the Interest amount you don't record any account details.
Thankyou.