Keep missing calls at night - can someone talk me through how to set up iPhone please?

[Squeeeeek]

I usually switch the little button on the side down so games / emails etc don’t wake me up at night.
I do need to have the phone ring or text ping in case my children need me overnight though.

I’ve googled that I apparently need to have their contacts set to emergency bypass (done), in focus I’ve set their contacts to allow notifications but when I test it, they call and the phone does vibrate but not actually ring.

what am I doing wrong?

I think you need to keep your sound on (so don’t slide the button in the side down), but turn on do not disturb. You can set do not disturb to come on for the same time each day, or put it on when you need to.