I know this is self hosted, but if you go away for a time, your infra will probably stop too, so this makes sense for a service rather than something you host.
I've thought about starting a service for this. Have the ability to send messages to different contacts through email, sms, or pre-recorded message.
I even thought about making a physical device that you could press, say every day, and it would send an API call to the service and realize you're still alive.
Is this something that people would actually consider paying for?
I do automatic monthly donations to the Frigate project. It's provided a ton of value so me, so I support the project on an ongoing basis through a gitbub sponsorship: https://github.com/sponsors/blakeblackshear