Wi-Fi Calling functionality is currently supported on the following:

Apple

iOS devices running iOS 15.7 or newer.

Android (please be sure to have the lastest software updated)

Samsung Flip 3, Fold 3
Samsung Flip 4, Fold 4
Samsung Flip 5, Fold 5
Samsung S23, S23+, S23 Ultra
Samsung S22, S22+, S22 Ultra  
Samsung S21, S21+, S21 Ultra
Samsung A03
Samsung A14
Samsung A32

Coming soon...

The dates for release for the following Samsung models is still to be determined:

Samsung S20, S20+, S20 Ultra
Samsung Galaxy Note 20 

The following Android devices do not support Wi-Fi Calling.  If you desire this feature, please visit a retail store for upgrade options.

Samsung A02, A10, A12 & A50 
Samsung Galaxy Note 10+ 
Samsung Galaxy S10e, S10, S10+
Samsung Galaxy S9, S9+
ATEL FR150
CAT S48C 
LG G8X
Motorola G6 Play  
Motorola G7 Power
Motorola E6 Surf
Motorola G8 Power
Sonim XP5 
Sunbeam
TCL Flip 2