Welcome to the community!
Are you able to receive text messages? Have you verified that the phone has the correct SMS message centre (SMSC) number? It's possible the number might have gotten deleted following the update. The SMS message centre number for Fido is: (514) 993-1123 (see here and here). You should be able to find the SMSC under the messaging app's settings. For Samsung OneUI 3.1, Messages --> Settings --> More Settings --> Text Messages --> Message Centre. Other devices might have their menus organised slightly differently, but it should be similar.
Hope this helps 😀
Good morning @vacayinacup , sorry to hear that you cannot send texts on your new device. A couple of questions for you. Did you restart your phone? Did you try removing SIM card and reinstall again? Have you checked the apn settings to see if they are correct? See here https://forums.fido.ca/t5/Phones-and-Devices/Fido-s-APN-amp-MMS-Settings/ta-p/118683
A few things that may help.
Also I should have asked your device type. Let us know