Please tell me:
- Did you add your mobile number incl. country code in this format: +48123456789 in Todoist's Settings -> Reminders (on the web-app)?
- Did the "Send a test" option work?
- Did you try to send a test through each of our 3 outgoing hosts (the US host and 2 Canadian hosts - you can select them when editing your number from the "number to send from" drop-down menu; when testing the Canadian hosts, please choose "Elsewhere" as your location)?