It has been sometimes for me to play around the Application User (and manage the security roles) via the classic UI.
However, during recent updates, it has been removed.
Currently, we have to do the job in Admin Power Platform.
Below are the steps:
- Head over https://admin.powerplatform.microsoft.com/
- Be sure you are selecting correct environment.
- Choose settings, and click on Application users as below screenshot:
4. You may add Application User here, ensure you have added into Azure Active Directory and give proper rights before doing this.
5. You can manage the security roles of Application User as well.
I hope this article can help some of the guys who struggling on finding the existing Application User interface in classic UI.