403 Error When using POST to receive Report Embedded Token

[Anonymous]

I created a simple Angular project to access the Power BI API. I am following the workflow of the App Owns The Data. My first POST call received an access token with no issues which is as follows:

(client_id, username, and password data removed from code post)

I am using my account which is the owner of the workspace and the owner of the registered Azure app.

//API call to get the access token
      const POSTbody = new HttpParams() 
        .set('client_id','client_id')
        .set('grant_type','password')
        .set('resource','https://analysis.windows.net/powerbi/api')
        .set('username', 'username')
        .set('password', 'password')
      
      this.http.post('https://login.microsoftonline.com/common/oauth2/token',POSTbody).subscribe(
          res => { console.log(res);
            accesstoken = res.access_token;
                 console.log('Access Token: ' + accesstoken)},
          err => { console.error(err); })

The second POST call which is to https://api.powerbi.com/v1.0/myorg/groups/... using the access token from the first API call is returning a 403 (Forbidden). This is the second call:

(access_token contains the token from the first API call, group ID and report ID data removed from code post)

var headers = new HttpHeaders();
    headers.append('Authorization','Bearer '+ access_token)

let url = 'https://api.powerbi.com/v1.0/myorg/groups/ID/reports/ID/GenerateToken';
   

      const Embedbody = new HttpParams()   
      .set('accessLevel','View')
      
      this.http.post(url,Embedbody
        ,{headers:headers}).subscribe(
          res => {console.log(access_token)},
          err => {console.log('ERROR!')},
          
      )

I verified in Azure that my registered app as the correct permissions:

Windows Azure Active Directory:

    Access the directory as the signed-in user

    Read all users' basic profiles

    Sign in and read user profile

Power BI Service (Power BI)

    All DELEGATED PERMISSIONS except  View all contet in tenant.

Has anyone run into this issue before using the API call in an Angular app?

Is there way to receive more details in the 403 error message?