It is recommended that at least one valid contact is configured for the security center. Microsoft will notify the security contact directly in the event of a security incident and will look to use a telephone number in cases where a prompt response is required.
Without a telephone number set, Azure support can’t contact
Set a telephone number for security center contact
The following example will fail the azure-security-center-set-required-contact-details check.
The following example will pass the azure-security-center-set-required-contact-details check.