When you want to take a group photo, but no stranger is around to take one for you (or you don't want to hand them your expensive new smartphone), you can use your iPhone's camera timer to get the job ...
You can set up Face ID on an iPhone in just a few seconds in the "Face ID & Passcode" section of your phone's Settings app.
You can set a timer on your Samsung Galaxy S10 camera to take a photo. The feature can be used with both the front and rear cameras.