How can I take a screenshot on an iPhone while Guided Access is on? I’m trying to take a screenshot of a problem that’s occurring with Guided Access on my iPhone. Is this possible?

I’ve had no luck with the usual method of simultaneously pressing the Home and Power buttons. This limitation exists even before I tap the Start button within Guided Access. Just being within the initial screen keeps the screenshot function from working. 

I tried to find an answer to this question via standard web search, but found nothing. 

Note: I’m using a beta version of iOS 13, but I assume that this same problem exists in iOS 12 and earlier.
You can use the AssistiveTouch feature built into iOS. AssistiveTouch gives you a software equivalent of Home button which can be used to perform a variety of device operations.

To enable AssistiveTouch go to Settings app → General → Accessibility → AssistiveTouch.



Once enabled, you'll notice a gray colored translucent overlay button on your device screen. Tap on the AssistiveTouch button → Device → More → Screenshot to capture a screenshot without touching any physical button on your device.







The captured screenshot can be viewed in the Photos app normally.