I can't send texts from the US even after adding funds to my wallet to pay as I go

As per title. Outside of the coverage area (Quebec), I have the option to either buy an add-on, or pay-as-I-go from the balance in my wallet. I've transferred funds to my wallet, but it still won't send texts.

Roaming is on, airplane mode is off, and I can't find anything in my iphone 7 settings that would prevent texts from sending out. It must be a coverage issue, but I have the funds there. What gives?