I am able to share experiences with spacial targeting on iPad, but can not open the same link on iPhone - same iOS version 11.2.1 on both.
It uses the Apple ARKIT technology here - and Apple decided to only support newer devices starting with iphone 6s / ipad pro
If your device is older - it won't work.
never heard of an Iphone 7S.
The tracking algorithms behind this spatial target are Apple ARkit based - no manual load needed, nor possible.
If thingworx view itself doesnt show the experiences for ARkit (all the experiences marked with ST in the front in the gallery of thingworx view) - than your device is most likely not ARKIT capable.