Extract responses associated with surveys within a brand.

I am trying to come up with a solution to extract all responses associated with surveys within a brand. I went though different posts and have come up with the following process but when when I execute the some of the API on postman, I do not get the expected response.
It will be great if someone can help by pointing out the issue.
1)Access the account to get the API token
2) Call the API https://[data center].qualtrics.com/API/v3/libraries (pass the API token )
Response - we get the list of library id associated with the account.
3) Call the API https://[Data Center].qualtrics.com/API/v3/libraries/[library id ]/survey/surveys
Response : I do not get the list of survey id that are associated with the library.
Reference : https://www.qualtrics.com/community/discussion/9890/get-survey-json-from-library#latest
Issue : I do not get the list of surveys.
Questions: Is there another API that I can use to get the list of all the surveys that are associated with an account ?
4) Call the API to get the responses :

1. Start Response Export: (In the API body, pass format as CSV. On successful execution, this will give you progress ID to be used in next API) https://api.qualtrics.com/instructions/reference/responseImportsExports.json/paths/~1surveys~1%7BsurveyId%7D~1export-responses/post


2. Get Response Export Progress: (This will give you file ID to be used in next API) https://api.qualtrics.com/instructions/reference/responseImportsExports.json/paths/~1surveys~1%7BsurveyId%7D~1export-responses~1%7BexportProgressId%7D/get


3. Get Response Export File: (On successful execution, save response to a file. Don't change the file name) https://api.qualtrics.com/instructions/reference/responseImportsExports.json/paths/~1surveys~1%7BsurveyId%7D~1export-responses~1%7BfileId%7D~1file/get

Response : On the the third step, I get an encrypted file on postman, the file cannot be downloaded.
Issue : I cannot find the file on my hard disk not can I view the data on Postman.
Questions:What should I do in order to download the file to my hard disk.
Reference :https://www.qualtrics.com/community/discussion/11015/how-to-store-data-into-a-downloadable-csv-file#latest
Any suggestions, pointers will be really helpful.