Yes, the XS series iPhone requires a wireless charging receiver to enable wireless charging. This is because the body itself does not have the ability to convert electromagnetic fields into electricity. During wireless charging, the charger sends a signal through the electromagnetic field to the wireless charging receiver, which converts the signal into electricity and transmits it to the phone for charging.
Therefore, unless this technology is directly integrated into the phone, users will need to purchase additional wireless charging receivers to achieve wireless charging.
The iPhone XS supports wireless charging and does not require an additional receiver. Just a wireless charger.