Ron from Naples, Florida has trouble connecting to the internet when he’s in restaurants and other public places. I told him to turn off his phone’s Wi-Fi connection, open the Phone app and dial *3001#12345#*. Then, press call.
This unlocks your iPhone’s secret menu. If you are using iOS 14 and later, then the hidden field test mode interface has been redesigned. To access Field Test Mode on iOS 14, follow the same steps listed above. You will then be taken to a dashboard where you can see your LTE dBm reading and other metric data.