From what I've been told and led to believe, the KeyTV system does not support WiFi. On the front of the KeyTV box are two connections for satellite TV and on the rear, there's one input from the rooftop antenna (TV/FM) and 5 outputs (Radio, TV1 TV2, TV3, TV4)
I believe the only "connection" between KeyTV and the 4G LTE antenna is that they are co-located on the roof in the same place. Other than that, there is no "interconnection of the systems".. The 4G LTE is separate from KeyTV and does not connect or interface with KeyTV.
You can review the "how to" videos at Keystone's website at this link:
https://www.keystonerv.com/owners/how-to-videos/