Well, first of all, ignore any/all advice about systemd.
systemd may be good for the experts (it was designed for and by experts), but is useless for us ordinary folk.
This question is the most frequently asked of FAQs. There should be (but isn't) a straightforward, RPI-approved, answer to it.
There are sensible ways to do it using any/either of:
The easiest and most straightforward to setup is the last in the above list.
Mind you, I said the easiest, but not necessarily the best. For my own projects, I always use #1 in the above list.
Anyway, there are lots of examples of various people's opinions on the subject strewn around this forum. It should not be too hard to find them.
"L'enfer, c'est les autres"
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