What is the error you are getting? Listen to this video that shows how to enable wi-fi calling on the iPhone : 

The message I get when I try to enable wifi calling in Settings (which is currently OFF) is “To allow Wi-if calling on this account, contact Koodo”. I called the so-called customer service phone number and the bot told me that i would receive a text message, and then a call-back. I tried eight times this morning and did not receive any txt message.

I followed your directions above in the video but I only receive this message “To  allow WiFi calling on this account, contact Koodo”.

@JudyL try updating your physical “e911” address here https://telusidentity.telus.com/as/authorization.oauth2?client_id=63ef8ba2-8434-4d63-9eef-876441d760b7&response_type=code&scope=ciiotp+sub_profile&redirect_uri=https://ent.telus.com/acmegw-android/entitlement/e911 and then enabling Wi-Fi Calling.  Does that help?   

Can you check your addon in selfserve to see if you had the “volte access” addon there? It was one of the provisions for wifi calling.