For whatever reason, I cannot find that option in the shortcuts app 
I wonder if it might be device specific (seems weird, but it’s the only reason I can think of, unless the search function is just not working correctly)
edit: Figured it out, there is no direct restart action, you must choose shutdown, and then set shutdown to restart.
edit 2: I like how the grumpy emoji pushes its way through the strikethrough, made me chuckle.
Siri also natively recognizes “Reboot”, “Shutdown”, and “Power off” but asks for similar confirmation. Although I typically say “Reboot my phone” as she doesn’t always get the context with just “Reboot”.
Sharing because I went a year without realizing this 
I don’t know the answer to your question, but your comment did make me realize that from the disabled biometrics state you can then press vol up + vol down + hold power off and that will perform a hard reset getting you into BFU.
Yea there’s no instant BFU solution as of now.
Every shortcut will still require you to push the button for confirmation but they can be quicker depending on your situation. If I’m in a stressful quick thinking situation, swiping that power off button may kill a extra second or two vs clicking 2 buttons.
Scenario: Your phone is in your pocket, you realize it needs to be in BFU ASAP
Pull out the phone, screen lights up, tap shortcut , tap shutdown, looks less suspicious than panic tapping a button several times or holding buttons.
For anyone new reading this thread be sure to check out the quickest factory reset (find my bypass). This is the fastest kill switch like option on iOS.
I really wish Apple would create a quicker and more convenient way to restart or shut down an iPhone. I really like Google’s method, where I can press the power and volume up buttons to get a menu to restart or shut down. It’s obvious, fast, and intuitive. I always do this before I go through passport control in the US.
Is there any way to enable shutdown/restart without having to provide a password or facial recognition? If you don’t have facial recognition registered, when trying to shut down you’ll have to enter the password, and that takes quite a while.
Another thing I noticed is that the automatic restart/shutdown also doesn’t work. It’s configured, but it doesn’t restart/shut down the phone at the set time.
My guide is for iPhones at a normal unlocked/locked state that doesn’t require the password. You will not be able to automate a scheduled shutdown/restart since it still requires user input.
The normal shutdown method that always works is holding down left volume button + power button
Yes a restart at least. I posted this method earlier in the thread and here is the Apple article.
Edit: I missed @iHateKYC2’s method of vol+power+slide as well. So 2 options.
New information about mitigating iOS notification remnants.