Becoming a British citizen on EU settlement settled status

Hi All.
I would need someone to shed some light on this please.
My children 15 and 3 years old. Both EU citizen got their settled status last year based on their Dad's Settled status.
My eldest (15) is just 3 years and 4 months in the UK and my youngest (3 )was born in the UK.
When can I apply for their neutralisation please. Do I have to wait till they fulfill their 5 years residency in UK please?
Thank you

Children are not naturalised, but registered as British citizens.

For the child born abroad, they can be registered as British citizens when
(a) at least one parent has either become a British citizen or applied to become one AND the other parent and child both have settled status or ILR, OR,
(b) the child has lived at least 10 years in the UK.

So, what is the British citizenship status of the two parents of the children?

And how long have they lived in the UK?

For the child born in the UK, they can be registered as a British citizen now as at least one of the parents has settled status.

The form to use is Form MN1.