Unable to send SMS from Macbook

Hi,

I recently switched to a new carrier (Bell to Virgin) and I notice that I can no longer send SMS Text Messages (the green messages) from my Macbook. My regular iMessage texts (the blue messages) are going through just fine.

I can also send SMS Text Messages from my iPhone, it's only that they're not working on my Macbook.

I have Text Message Forwarding turned on for my phone.

What can I do to fix this?