Added remark about authenticationSource claim in combined local and social sign-in

A user encounters the `AADB2C90037` error without this change

Author: esinmy

articles/active-directory-b2c/custom-policies-series-sign-up-or-sign-in-federation.md

@@ -225,7 +225,7 @@ Notice the claims transformations we defined in [step 3.2](#step-32---define-cla
 
 Just like in sign-in with a local account, you need to configure the [Microsoft Entra Technical Profiles](active-directory-technical-profile.md), which you use to connect to Microsoft Entra ID storage, to store or read a user social account. 
 
-1. In the `ContosoCustomPolicy.XML` file, locate the `AAD-UserRead` technical profile and then add a new technical profile by using the following code: 
+1. In the `ContosoCustomPolicy.XML` file, locate the `AAD-UserUpdate` technical profile and then add a new technical profile by using the following code: 
 
     ```xml
         <TechnicalProfile Id="AAD-UserWriteUsingAlternativeSecurityId">
@@ -517,6 +517,7 @@ Use the following steps to add a combined local and social account:
     ```xml
         <OutputClaim ClaimTypeReferenceId="authenticationSource" DefaultValue="localIdpAuthentication" AlwaysUseDefaultValue="true" />
     ```
+    The same code should be added to the `UserSignInCollector` self-asserted technical profile. Otherwise, a user encounters the `AADB2C90037` error during local sign-in at orchestration step #6, since the `authenticationSource` claim is not assigned any value and the `alternativeSecurityId` claim is not found.
 
 1. In the `UserJourneys` section, add a new user journey, `LocalAndSocialSignInAndSignUp` by using the following code: