I can't use WiFi calling

[HenroGamay]

When I turn on my wifi calling and I have only 1 sim on it and it doesn't appear on the wifi calling. I try turn and off and it still doesn't work. When I'm trying to make a call it doesn't work for me. I watch some youtube and doesn't help me at all 

Can anyone help me with this problem 

[VinceLawrence_A15]

Your carrier doesn't support that

[ljbulusan]

That depends in your carrier, that will only work if your sim have the VoLTE enabled (the one you're seeing in the status bar on some devices if you've seen one)

[Members_DVfIxHz]

Bakit