What happens to your business if you die?

How often do solo Indie Hackers have a proper succession plan in place?

In my case, if I died before my time, all of my assets could be liquidated and my wife and kids would inherit the lot.

But what about my side-project? It's beginning to make money but there's nobody else who knows how to run it, build it, improve it and has access to all accounts and systems. I don't have a backup plan.