No verification code sent to install messenger

Hi All,

activated Garmin in reach via Garmin explore website. Never got a verification code via sms to simply install messenger app. Got it activated, device working and all good. However still dependent on the messenger app for full use of device. Have tried time and time again to get the sms code but nothing. Without use of the messenger app the device doesn’t work at best capability and just cannot verify this simple app download on iphone.

Any ideas???