Hi @Tiago Catarino,
Based on your query, I understand you are trying to configure RIOT games as IDP in Azure AD B2C.
As per your requirement, if you would like to configure any of generic IDP, please go through this document: Set up sign-up and sign-in with generic OpenID Connect using Azure Active Directory B2C. Please follow the document completely for configuration.
Once the user is signed in the next steps will be proceeded by user journey attached to the IDP. Here is the document you can follow: Add the identity provider to a user journey. Once the user is authenticated this user journey will carry the user through orchestration steps.
I hope this information is helpful. Please feel free to reach out if you have any further questions.
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