You can. You call the school. That's what people did before schools started allowing phones everywhere.
If there is an emergency, you'll need to call them anyway. No school is just gonna let your kid leave because the kid says it's okay.
Sincerely, a fellow dad

If this "yearning for more" feeling has been around for years, I think you need to consider taking a break from work. You need to get out there and explore. You need to find out what that "more" is.
You're doing the same thing day in and day out. How do you ever expect to figure out what "more" is unless you go looking for it?
It could be as simple as burnout or the need to see the world. It could be a new career you never even thought about. Maybe you'll just discover you like walking through forests. Maybe you find a new city to live in that's better. Maybe nothing really needs to change or maybe everything does.
If that's not something you can and want to do, you'll at least want to do some soul-searching. Does it feel like there's a hole in your life? Start journaling. Talk to a therapist. If you can figure out the shape of the hole, you may figure out how to fill it.