Not receiving text message for online purchases

Hello, I recently changed my phone number in the Monzo app, the number is from New Zealand however it allowed me to change it, when I attempt to use it online, a MasterCard ID Check occurs saying they’ve sent me a text message, however I don’t receive it, any ideas?

You’re probably best off contacting monzo using the app chat.

Is it a voip number?

Monzo normally sends the ID check flow through the App the sms is an option if the app flow does not work