Transmit your BTC to your child

I live in France.

As said, I would like to know the different ways to transmit my BTC before/after my death, with hot/cold wallet.

Please note that I recently spoke about this with a notary, who as a matter of fact is not a specialist on the subject.

He explained to me the difficulty of proving that my hot wallet is indeed mine and not that of another person.

Bonus question: if I submit my seed to the Study. How do I ensure that a notary does not access my wallet?

Thank you for your indulgence.