Angular MSAL not recognizing JWT token from Azure B2C SAML Technical Profile redirect

Question

Context:
We have an existing Angular app that is authenticating with Azure AD B2C tenant users using MSAL 2.0 and PKCE flow. Configuration was done using B2C Custom Policies. We have a requirement to support "SP Initiated SAML SSO" with third-party external vendor.

Implementation:
1#
Enhanced Custom Policies by creating SAML Technical profile section in TrustFrameworkExtensions, by following documentation links like below https://learn.microsoft.com/en-us/azure/active-directory-b2c/identity-provider-generic-saml?tabs=windows&pivots=b2c-custom-policy
https://learn.microsoft.com/en-us/azure/active-directory-b2c/identity-provider-adfs-saml?tabs=windows&pivots=b2c-custom-policy

2#
Also, followed links like below to configure linking of local user with federated user

https://learn.microsoft.com/en-us/azure/active-directory-b2c/user-profile-attributes?WT.mc_id=AZ-MVP-5003445#identities-attribute

By running the policy, SAML AuthN request was sent to external SAML provider & successfully received SAML Response. By redirecting to https://jwt.ms, equivalent JWT tokens are received in the id_token parameter & access_token parameter
Eg:- (Policy triggered with below link)
https://

Answer 1

Hello @Bhanu Reddy and thanks for reaching out. Most possible cause of AADB2C90079 error being thrown is app registration being set as web (confidential), which expects a client secret. Configure it as SPA (public) and let us know.

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