"How to find iPhone" is one of the most popular Google search queries as of this writing. Perhaps the iOS device is slipping out of pockets as Apple owners scramble to secure the best Black Friday 2021 deals as the holidays draw near. No matter the reason, thanks to the Find My app, you should be able to locate your lost iPhone within seconds.
In order to find your misplaced iPhone, it should have already been setup within the Find My network. (This is done by navigating to Settings > Your Name and toggling on "Find My.") If your phone isn't in the Find My network, unfortunately, you cannot use the Find My app to locate your device. Secondly, you may need another iOS device (signed in with your Apple ID) to facilitate Apple's Find My process.