1. If you have not already, install QR Code Reader on your iPhone and start the QR Code Reader app. 2. Position the phone to scan the barcode with your phone's camera. When the scan is successful Go to Settings > [ your name ] > Sign-In & Security, then tap Two-Factor Authentication. Tap Edit (above the list of trusted phone numbers), then enter your device passcode when prompted. Add a number: Tap Add a Trusted Phone Number, then enter the phone number. Remove a number: Tap next to the phone number. Method 1: Star Code Commands. For our first touchscreen testing method, it’s time to take a look at the touchscreen itself with a few built-in troubleshooting tools. Before I get into what they are, here are a few dialer codes —also known as star codes— that may be compatible with your device. iPhone 11 (left) vs Pixel 3 (right) (drag the slider to compare the two photos) It’s far from a new thing for phones to pack such a sensor, but it’s great to see Apple adding one here anyway. Open the Camera app from the Home Screen, Control Centre or Lock Screen. Select the rear-facing camera. Hold your device so that the QR code appears in the viewfinder in the Camera app. Your device will recognise the QR code and display a notification. Tap the notification to open the link associated with the QR code. Published Date: January 03 To drive things home, I’ll walk you through two methods you can use to test your code as a budding developer. 1. Manual Testing. With this method, developers create human-readable test cases to be performed manually—meaning literally by a human—without the support of automated tools. TestM iPhone testing app. OK, with that out of the way, the diagnostic mode offers 26 tests, which range from testing the cameras, touchscreen, microphone, and even the haptic engine, to a Open the Phone app, tap the Keypad, and then type *#0*##0*#. A diagnostic screen pops up with buttons for a variety of tests. Tap Red, Green, or Blue to test those pixel colors. Tap Receiver to But these codes will be able to tell you if your calls and texts are being hijacked. To use these codes, dial them in your iPhone’s phone app. Then simply tap the call button. Here are the 3. Scroll down and tap Change Passcode. 4. Enter your old passcode. 5. Your iPhone will now ask you to enter a 6-digit passcode. Before you enter your new passcode, if you'd prefer a 4-digit code K2SH.