Unable to call Canada from Ireland

Hello Rogo,
If your data is working but your outbound calls to Canada are failing with a 'cannot reach the number' message, it usually comes down to roaming technicalities.
Even if your phone is used to international travel, the local roaming carrier you are currently connected to might handle international routing strictly.
Try dialing +1 followed by the 10-digit number (e.g., +1 514 XXX XXXX). To get the + sign on your keypad, hold down the 0 key.
Do not just dial the 10-digit number by itself, as the local network won't know to route it back to Canada.
Make sure you are dialing the Canadian number using the full international format. 
Many global networks have completely shut down their older 2G/3G networks and handle all voice calls over LTE (VoLTE). If your phone's VoLTE roaming is toggled off, calls will fail immediately.
iPhone: Go to Settings > Cellular > Cellular Data Options > Voice & Data, and ensure VoLTE is turned on.
Android: Go to Settings > Connections > Mobile Networks, and ensure VoLTE calls or VoLTE Roaming is enabled.
If the above tips don't work, try going into your phone's network settings, turning off 'Automatic Network Selection,' and manually choosing a different local partner carrier from the list. Sometimes a specific local network handles voice roaming better than another.
Here is an FAQ with more details about this https://fizz.ca/en/faq/I-cant-make-any-calls-on-my-phone-why
If you have any other questions feel free to reach us at https://fizz.ca/en/support
-Alexandru, Community Moderator