Trading account for linking to minor demat account

Hi,

I want to open a demat and trading account for minor.

Demat for minor is possible and easy.

Trading account for minor there is lot of confusion. Can we open or need to open guardian trading account and map with minor demat? Or what else?

At which full service broker & DP can i open paperless trading and demat account for minor?

Other than hdfc icici kotak iifl ?