does apple send popup messages to change passcode

No but it is possible that IF you have a work profile installed on the phone, the profile may. Is this a work phone?

If the pop up looked or came up from Safari try resetting it. Scammers can plant malicious cookies causing this behaviour.

Resetting Safari. Close Safari completely from the app switcher window by double clicking the Home button and swiping up the Safari preview pane until it disappears from the screen. Then go to Settings > Safari > Clear History and Website Data. Then do a forced restart. Hold down the Home and Wake/Sleep buttons at the same time for about 15-20 seconds until the Apple logo appears.

tototoov wrote:

does apple send popup messages to an iphone to change a passcode?

There are unusual cases where an iPhone will prompt you to change your passcode. But it may be a scam also. Either way, it is perfectly safe to ignore the message and go to Settings/Touch ID & Passcode and change your passcode. Just don't ever do it through a response to a message of any kind. As it recurs when you reboot the phone it is probably legitimate. Do you have a 4 digit passcode with repeated digits, perchance?

It's not Apple it's your device. After iOS 9 Apple implemented 6 digit passcodes. If you didn't opt for the feature when setting up the device after the update, the device likes to reminds you to do so with said pop-up.

Then ignore it. If it comes back change your passcode using the Settings app. If that stops it the message was legitimate. A scam won't know if you changed it or not.

It's something that Apple programmed into the device. So the message is generated in your device, but it is really Apple that programmed it to do that.

One thing to check: Go to Settings/General and scroll to the bottom. Do you see a category "Profiles" or "Management?" If there's a profile installed it could have generated the message. The ONLY way a profile can be put on a phone is if you download it (perhaps to use a non-Apple app or app store) or if you have a company MS Exchange email address on your phone.

FWIW I have 4 digit passcodes and 9.3.2 and I have not been prompted to change them. That's why I asked if this looked like a Safari pop up and if so to clear the cache.

Well, that is the first question I asked on the first reply.... 😉

I took screenshots when it happened to me. I was on the home screen and night shift just turn on. I was confused, needless to say. So I asked this community about it.

Please read here > Night shift

tototoov wrote:

does apple send popup messages to an iphone to change a passcode?

Apple doesn't really care if you even use a screen lock passcode or not, and they have no way of knowing if you do, or if you have disabled it in settings, or whether you use a 4-digit, 6-digit or complex passcode. They are not monitoring your device and don't care how you configure your security of your property. Anything that generates that popup is either local software on your device, or part of an exchange or managed deployment profile or some such local feature.