You can turn on Verizon's Advanced Calling 1.0 (VoLTE) by going here: https://www.verizonwireless.com/wcms/consumer/advanced-calling.html and clicking the "Get Advanced Calling" button.
I was able to successfully add it to my account and change the "Enable LTE" setting on my iPhone 6 to "Voice & Data" instead of just Data. I haven't had a chance to try and make a call with it just yet though.
I was able to successfully add it to my account and change the "Enable LTE" setting on my iPhone 6 to "Voice & Data" instead of just Data. I haven't had a chance to try and make a call with it just yet though.