Anonymous access to Azure AD B2C

Anon_SUSI.xml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<TrustFrameworkPolicy
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                      xmlns:xsd="http://www.w3.org/2001/XMLSchema"
                      xmlns="http://schemas.microsoft.com/online/cpim/schemas/2013/06"
                      PolicySchemaVersion="0.3.0.0"
                      TenantId="tenant.onmicrosoft.com"
                      PolicyId="B2C_1A_Anon_SUSI"
                      PublicPolicyUri="http://tenant.onmicrosoft.com/B2C_1A_Anon_SUSI">

	<BasePolicy>
		<TenantId>tenant.onmicrosoft.com</TenantId>
		<PolicyId>B2C_1A_TrustFrameworkExtensions</PolicyId>
	</BasePolicy>
	
	<BuildingBlocks>
		<ClaimsSchema>
	
			<ClaimType Id="anonUser">
				<DisplayName>Anonymous User</DisplayName>
				<DataType>boolean</DataType>
				<AdminHelpText>Specifies whether the user is anonymous.</AdminHelpText>
				<UserHelpText>Specifies whether the user is anonymous.</UserHelpText>
			</ClaimType>
	
		</ClaimsSchema>	
	</BuildingBlocks>
	
	<UserJourneys>
		<UserJourney Id="AnonSignUpOrSignIn">
			<OrchestrationSteps>	  
				<OrchestrationStep Order="1" Type="SendClaims" CpimIssuerTechnicalProfileReferenceId="JwtIssuer"/>
			</OrchestrationSteps>
		</UserJourney>
	</UserJourneys>

	<RelyingParty>
		<DefaultUserJourney ReferenceId="AnonSignUpOrSignIn"/>
		<TechnicalProfile Id="PolicyProfile">
			<DisplayName>PolicyProfile</DisplayName>
			<Protocol Name="OpenIdConnect"/>
			<OutputClaims>
				<OutputClaim ClaimTypeReferenceId="displayName" PartnerClaimType="name" AlwaysUseDefaultValue="true" DefaultValue="Anon User"/>
				<OutputClaim ClaimTypeReferenceId="givenName" AlwaysUseDefaultValue="true" DefaultValue="Anon"/>
				<OutputClaim ClaimTypeReferenceId="surname" AlwaysUseDefaultValue="true" DefaultValue="User"/>				
				<OutputClaim ClaimTypeReferenceId="anonUser" AlwaysUseDefaultValue="true" DefaultValue="true"/>
				<OutputClaim ClaimTypeReferenceId="objectId" PartnerClaimType="sub" AlwaysUseDefaultValue="true" DefaultValue="123456"/>
				<OutputClaim ClaimTypeReferenceId="tenantId" AlwaysUseDefaultValue="true" DefaultValue="{Policy:TenantObjectId}"/>
			</OutputClaims>
			<SubjectNamingInfo ClaimType="sub"/>
		</TechnicalProfile>
	</RelyingParty>
</TrustFrameworkPolicy>

https://medium.com/the-new-control-plane/anonymous-access-to-azure-ad-b2c-2e2c81bb0f7f