VoLTE SUpport

I have Hologram SIM card. I use FiPy and can deliver data to Hologram or any other cloud sites.
With FiPy firmware i do not have to select the carrier - it is done automatically for me, and most of the times it picks up AT&T.

My question is: is your SIM compatible/supports VoLTE which I know is implemented and available by AT&T.