Premium Bond Alternative

I am a convert and parents are not muslim.
My parents want to buy government premium bonds for my son. They have asked for an alternative that would be halal as they respect our faith.
I’ve looked into it and there seems to be no easy alternative I could tell them to do. Is there any halal thing my parents could gift my son like savings but with a certificate?
I’ve tried to find sukuk but I am totally lost and if I’m lost they will not know what to do.
They’re looking for something they could gift each birthday that isn’t just money.

May Allah bless you.

@ibrahimkhan can advise further inshAllah.

Have you looked at the gfh sukuk fund available through IFG?