iPhone 7 restarts itself

I had my phone set to automatically update on charge at night.

i noticed after your advice it wouldn't update.

i been trying this whole time to update since your response and it finally went through and fixed the problem.

for some reason the update would keep shutting the phone off. Then I would have to restart the update all over agin.

"i guess it was a glitch."

thanks for your help for fixing this problem.