iOS 13 is released and the launch of the iPhone 11, iPhone 11 Pro and Pro Max the way that you clear the RAM on the devices has changed.
Zollotech has put together a comprehensive video that shows us how to clear the RAM on your iPhone without having to do a full reset on the phone.
As you can see in the video, you will need to turn on Assistive Touch on your device in order for this to work. This can be done by going to Settings > Accessibility > Touch > Assistive Touch and turn it on.
Once this is done you need to press the volume up, then the volume down and then press and hold the power button and release it. You then need to press and hold the Assistive Touch Home Button, then enter your passcode and your RAM has been cleared.
Source & Image Credit: Zollotech