Unexpected exception AccessDenied: User: arn:aws:iam::123456789:user/abc is not authorized to perform: sts:AssumeRole on resource: arn:aws:chime

Question

I have to generate a federated token using AWS STS for an authenticated Cognito User in the Cognito Pool. The problem is that when I run the code by following the documentation of aws-docs it returns me with this error:

unexpected exception AccessDenied: User: arn:aws:iam::123456789:user/abc is not authorized to perform: sts:AssumeRole on resource: arn:aws:chime:us-east-1:123456789:app-instance/xxx/user/yyy

I am trying for the past 1 week to solve this problem and have searched almost everything on the internet.

I have already tried some of these solutions but still no luck:

1. https://www.hava.io/blog/what-is-aws-security-token-service-sts#:~:text=AWS%20STS%20security%20tokens%20are,require%20access%20by%20other%20applications.&text=Using%20AWS%20STS%20you%20can,authenticated%20at%20your%20enterprise%20network.

2. AWS AssumeRole - User is not authorized to perform: sts:AssumeRole on resource

Here's my trust relationship IAM Role JSON file:

{
"Version": "2012-10-17",
"Statement": [
    {
        "Sid": "Statement0",
        "Effect": "Allow",
        "Principal": {
            "AWS": "arn:aws:iam::123456789:user/abc"
        },
        "Action": "sts:AssumeRole"
    },
    {
        "Sid": "Statement1",
        "Effect": "Allow",
        "Principal": {
            "Service": "lambda.amazonaws.com"
        },
        "Action": "sts:AssumeRole"
    },
    {
        "Sid": "Statement2",
        "Effect": "Allow",
        "Principal": {
            "Service": "chime.amazonaws.com"
        },
        "Action": "sts:AssumeRole"
    }
 ]
}

And here is my inline-policy of IAM Role:

    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": [
                "sts:GetSessionToken",
                "sts:AssumeRole",
                "sts:TagSession",
                "sts:GetFederationToken",
                "sts:SetSourceIdentity",
                "sts:DecodeAuthorizationMessage",
                "sts:AssumeRoleWithSAML",
                "sts:GetAccessKeyInfo",
                "sts:GetCallerIdentity",
                "sts:AssumeRoleWithWebIdentity",
                "sts:GetServiceBearerToken"
            ],
            "Resource": "*"
        }
    ]
}