I have added Microsoft IDP to Custom Policy using this link [https://docs.microsoft.com/en-us/azure/active-directory-b2c/identity-provider-microsoft-account-custom?tabs=applications][1]. The user can click the Microsoft Account button and use their MSA account to sign-up\sign-in. When the user signs up using MS acccount we'd like to validate the e-mail against our database. If the user's email is in our database, let them proceed and signup; otherwise we'd like to prevent them from signing up and display an error message. This would prevent creating a User in our Azure B2C AD. I used the following TechnicalProfile in
<ClaimsProvider>
<Domain>live.com</Domain>
<DisplayName>Microsoft Account</DisplayName>
<TechnicalProfiles>
<TechnicalProfile Id="MSA-OIDC">
<DisplayName>Microsoft Account</DisplayName>
<Protocol Name="OpenIdConnect" />
<Metadata>
<Item Key="ProviderName">https://login.live.com</Item>
<Item Key="METADATA">https://login.live.com/.well-known/openid-configuration</Item>
<Item Key="response_types">code</Item>
<Item Key="response_mode">form_post</Item>
<Item Key="scope">openid profile email</Item>
<Item Key="HttpBinding">POST</Item>
<Item Key="UsePolicyInRedirectUri">0</Item>
<Item Key="client_id">12344</Item>
</Metadata>
<CryptographicKeys>
<Key Id="client_secret" StorageReferenceId="B2C_1A_MSASecret" />
</CryptographicKeys>
<OutputClaims>
<OutputClaim ClaimTypeReferenceId="issuerUserId" PartnerClaimType="oid" />
<OutputClaim ClaimTypeReferenceId="givenName" PartnerClaimType="given_name" />
<OutputClaim ClaimTypeReferenceId="surName" PartnerClaimType="family_name" />
<OutputClaim ClaimTypeReferenceId="displayName" PartnerClaimType="name" />
<OutputClaim ClaimTypeReferenceId="authenticationSource" DefaultValue="socialIdpAuthentication" />
<OutputClaim ClaimTypeReferenceId="identityProvider" PartnerClaimType="iss" />
<OutputClaim ClaimTypeReferenceId="email" />
</OutputClaims>
<OutputClaimsTransformations>
<OutputClaimsTransformation ReferenceId="CreateRandomUPNUserName" />
<OutputClaimsTransformation ReferenceId="CreateUserPrincipalName" />
<OutputClaimsTransformation ReferenceId="CreateAlternativeSecurityId" />
<OutputClaimsTransformation ReferenceId="CreateSubjectClaimFromAlternativeSecurityId" />
</OutputClaimsTransformations>
<ValidationTechnicalProfiles>
<ValidationTechnicalProfile ReferenceId="REST-ValidateProfile" />
</ValidationTechnicalProfiles>
<UseTechnicalProfileForSessionManagement ReferenceId="SM-SocialLogin" />
</TechnicalProfile>
</TechnicalProfiles>
</ClaimsProvider>
i added REST API Call
<ValidationTechnicalProfiles>
<ValidationTechnicalProfile ReferenceId="REST-ValidateProfile" />
</ValidationTechnicalProfiles>
but is not working. ANy idea?