Many Google recovery codes are sent from "shortcodes" (5- or 6-digit numbers). Mobile carriers sometimes block these by default to prevent spam.
: Instead of an SMS, you can often choose to receive a phone call with the verification code. gmail password recovery via sms link fix
: Sometimes the app responsible for receiving texts hangs. Go to your device settings, find the Messages app, and clear its cache and data. Many Google recovery codes are sent from "shortcodes"
Before trying advanced methods, ensure the issue isn't on your end. SMS delivery often fails due to simple hardware or software settings. find the Messages app