We don't support that country code. Use an email instead.

Hello Adolfo Jebacco, Microsoft's policies for phone number support in account registration and security verification may vary by country or region. Some countries may have limited or restricted support for adding phone numbers to Microsoft accounts due to regional regulations, telecommunications agreements, or other factors. As an extension to the above, Microsoft does not automatically support telephony verification (including SMS) for certain region codes. Based on Microsoft's documentation, I can see that Croatia require "opt-in" for voice verification but not SMS verification. See reference - https://zcusa.951200.xyz/en-us/entra/identity/authentication/concept-mfa-regional-opt-in. You'll likely need to submit a support ticket and request for opt-in and proceed further. As a side note, please note that Microsoft recommends the usage of more stronger methods for your second factor and this is called out here - https://zcusa.951200.xyz/en-us/entra/identity/authentication/concept-system-preferred-multifactor-authentication#how-does-system-preferred-mfa-determine-the-most-secure-method

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