What am I doing wrong to get this error for Google Vision API

I have been getting a "Error opening File: gs://{gs-bucket-path}/{gs bucket folder path} - In VS code

I have tried it in Postman and receive "Error opening file: gs://{gs-bucket-path}/{gs bucket folder path} permission denied.

I have a Service Account created under the project for this OCR API project, I downloaded the JSON and ensure in PowerShell that the GOOGLE_APPLICATION_CREDENTIAL key/path is pointing correctly to my JSON file that I downloaded. I have set API keys and tried OAuth 2.0 credentials.

I am pretty new to doing APIs and having to deal with CRUD and JSON but have learned an ok amount of terminology with messing up so much.

I have set permissions under my account in the organization as Storage Object Owner Project IAM Admin Project Mover Storage Admin Storage Folder Admin Storage Object Admin Storage Object Creator Storage Object Viewer

Have also set the Service Account permissions under the Project as Storage Object Creator, Storage Object Viewer, & Storage Object User Removed it as Owner as I read on another post that its not a good idea.

I'm confused.

Here is my code from postman and the error i am receiving

POST https://vision.googleapis.com/v1/files:asyncBatchAnnotate?key={{key}} this is where I'm calling.

    {
  "requests": [
    {
      "inputConfig": {
        "gcsSource": {
          "uri": "gs://My-Path-To-My-GsBucket/My-Path-To-Folder&File.pdf"
        },
        "mimeType": "application/pdf"
        
      },
      "outputConfig": {
        "gcsDestination": {
          "uri": "gs://My-Path-To-Output-Folder/"
        },
        "batchSize": 1
      },
      "features": [
        {
          "type": "TEXT_DETECTION"
          
        }
        
      ]
      
    }

  ]
  
}

the response i get is "error":{ "code":403 "message": error opening file { my path} "status": Permission_denied

So i found a Postman video on setting up Google OAuth from the actual google cloud console, followed that guide, found out i had some information in the Auth URL wrong in the OAuth 2.0 set up on postman along with a Client Authentication was wrong. Fixed & ran that. Received a token, used as bearer and no error anymore. Onto the next step! TY so much for everyone's help.