You'll find it hard to make a crypto enthusiast entrust an exchange and another 3rd party for the inheritance. We are aware of scams and we are aware also that sons and daughters (siblings) can fight over what you left. If you don't want them to quarrel with each other, you would probably just let them learn cryptocurrency as early as possible and give them equally while I'm still alive.
That's why you can make two different policies and specify the amount you want to pass in each of the policies.
Send me your BNB address (bsc network) and I'll send you the policy for the test.