Welcome to Vodafone Community
I do not own the phone but as it's more than capable Vodafone hopefully should be adding that model to the list in wi-fi-calling
However even when the phone isn't in the list or supplied by them the phone still can use the feature going from past posts on the forum.
Have you tried getting it set up ?
Calling Over WiFi Set up.
Ask the agent to force the phone via sending an OTA configuration update that should provision your phone for Calling Over WiFi.
"Register for Vodafone Wi-Fi Calling
Text the word CALLING to 97888
This is a free text which will add the service to your account
You should receive the following confirmation text:
Thanks. We’ll add Wi-Fi Calling to your account in the next 24 hours and will let you know when you’re all set up.
If you’d like to discuss this with us, or if you have any other issues, you can find more info here or contact us
Once you receive the confirmation text, switch on Wi-Fi Calling in your settings
Go to Settings, scroll down and choose the Application icon
Choose Phone and scroll down until you see Wi-Fi Calling – select the box beside this option
A pop-up will appear asking you to confirm if you want to enable Wi-Fi Calling – tap OK"
Make sure Calling Over Wi-Fi is turned on in your myvodafone.
Calling Over Wi-Fi will only activate when there is no network connection. Test by activating Flight Mode on your phone.
Current Phone >
Samsung Galaxy s²² Ultra 256gb Phantom Black.
@Lukecharnett I dont own the a Pixel 6 either, but my work mate does and although he bought the Pixel direct from google he uses his Voda pay monthly sim in it & his WiFi calling works. I saw your post the other day and asked my work mate did it just work out of box or did he set it up, he told me that he set it up on the phone but had issues and spoke to tech support who with trial & error got it working for him.
It's offered for the Pixel 4A, the 5G & the 5 so I would assume the 6 & 6 PRO would be fine. So if you have set it up on your Pixel as @BandOfBriothers has already explained and you are still having no joy maybe contact technical support or even Google direct pixel support.
Also this thread maybe useful, its referring to the Pixel 5 but I doubt the phones software/andriod hasn't changed that much & maybe helpful in troubleshooting (I could be wrong)
Good luck sorting it