AWS Amplify, use Cognito attributes (sub, custom:userType) for IAM authenticated role to Read/Write on S3 bucket path

Question

I am developing an app using AWS Amplify where I need to store files. I want to use Cognito Attributes instead of Federated Identity ${cognito-identity.amazonaws.com:sub}. I got Schools, Teachers, and students. I want students to upload files to something like the below

"Resource": "arn:aws:s3:::s3-bucket-name/schools/${principalTag/custom:schoolID}/students/${principalTag/username}/"*

I tried Federated Identity > User Access > Attributes for access control > Use Default Mapping The user can log in but no IAM role is attached to the user.

S3 structure is

s3-bucket-name/
└── schools/
    └── school-id-1/
        ├── teachers/
        │   └── teacher-id-1/
        └── students/
            └── student-id-1/