https://learn.microsoft.com/en-us/entra/identity/saas-apps/proofpoint-ondemand-tutorial
Configure Proofpoint on Demand for Single sign-on with Microsoft Entra ID - Microsoft Entra ID |...
Learn how to configure single sign-on between Microsoft Entra ID and Proofpoint on Demand.
proofpoint on demandmicrosoft entra idconfiguresinglesign