403 error while downloading the attachment

Hi,

we are using some python scripts to download the attachments from JSM(Data Centre Version),
, but is giving the below message,
error code : 403
message : You do not have the permission to see the specified issue

The user credentials used to access the JSM is Admin Credentials and all permission are granted to the administrator in the project.

i have added the code here:

#downloadFile from jira server    
def downloadFile(jIssueID,extension):
    appConfig = kms.appConfig
    fileLocation=appConfig["configuration"]
    jiraConfig = kms.systemConfig
    jiraConfig=jiraConfig["JiraConfig"]
    logger.infoLog("Starting DOWNLOAD file function")
    directory=fileLocation["Attachments-Path"]+jIssueID
    if not os.path.exists(directory):
        os.makedirs(directory)
    # else:
        # for file in os.listdir(directory):
            # if file.endswith(".htm"):
                # return directory+"/"+file        
    
    try:
        headers={
            "Accept":"application/json",
            "Content-Type":"application/json"
        }
        url=jiraConfig["url"]+"/"+jIssueID #url : https://jsmuat.qwikcilver.com/rest/api/2/issue/
        response=requests.get(url,headers=headers,auth=(jiraConfig["id"],jiraConfig["password"]))
        logger.infoLog(response)
        logger.infoLog(response.text)
        attachment=response.json()["fields"]["attachment"]
        fileFound = False
        if attachment:
            for i in attachment:
                if extension in i["filename"].lower():
                    file=requests.get(i["content"],auth=(jiraConfig["id"],jiraConfig["password"]))
                    #logger.infoLog("Saving file at: "+directory+"/"+i["filename"])
                    if os.path.exists(directory+"/"+i["filename"]):
                        os.remove(directory+"/"+i["filename"])
                    open(directory+"/"+i["filename"],'wb').write(file.content)
                    fileFound = True
                    return directory+"/"+i["filename"]
                
        if not fileFound:
            logger.infoLog("No Attachment Found- Further Process Terminated")
            return "Not Found"

    except Exception as e:
        #print(str(traceback.format_exc()))

Please guide me in resolving the issue