iPhone 13 antenna location for EMF sticker application

Applying it near or on top of the antenna is going to block the signal trying to reach the antenna and you will have a very weak signal.

And honestly, those EMF blockers are for the most part, snake oil. To block the signal from reaching your body you would need to place it on the side of the phone that faces your body, the front screen. Placing it on the back like they say to do would accomplish absolutely nothing.

Locking yourself in your home would protect you more than putting a worthless sticker on your phone. They don't do anything. And it's been proven over and over and over that any radiation a cell phone emits is insignificant. But when you walk outside, you are bombarded by radiation. Radiation from the sun. Radiation from cell towers. A significant portion of the radiation we are subjected to comes from natural background radiation, which includes radon in the air, cosmic rays from space, and radiation from the Earth’s crust. The radiation emitted by your cell phone would be the least of your worries.

What exactly is the goal of the sticker?

Are you also going to label all of your cutlery with “sharp edge” labels ???

A mobile phone fundamentally emits RF.

No sticker changes that.

If you desire to reduce your exposure to RF … use a different style communications device.