Perform the following steps to disable email-based verification and enable SMS-based verification.

```bash
$ amplify add auth
 
? Do you want to use the default authentication and security configuration?
# Manual configuration

... Answer as appropriate

? Email based user registration/forgot password:
# Disabled (Uses SMS/TOTP as an alternative)
? Please specify an SMS verification message:
# Your verification code is {####}

... Answer as appropriate

Some next steps:
"amplify push" will build all your local backend resources and provision it in the cloud
"amplify publish" will build all your local backend and frontend resources (if you have hosting category added) and provision it in the cloud
```