Well, you can save your seed phrase so it can be passed after your death. Or pass it before that to your relatives whom you want to get your BTC. I suppose there are also many ways to do this, but I couldn't come up with them, I don't have such plans anyway.
You can literally pass on the seed phrases in your will and make sure you tell your relative(s) where it is.
On-chain passing-the-torch style transactions are also possible as others pointed out , but you want your dead man's switch to be failsafe and work properly the first time.