Salesforce (SF) integration - Download Files Stored as a URL in salesforce Attachment/Files

We have integrated Qualtrics and Salesforce through the standard connector but the survey allows users to upload files which are getting stored in forms of URL. Now these files URL is going to salesforce but when we are clicking to the URL it is asking for login before getting access to the files . But in salesforce we want to download the files from the URL and store it under Attachment/Files. So we make an api hit where using Basic Auth we are getting Statuscode=200 but when we are trying to make hit on the files URL, it is throwing an error as [Status=Temporary Redirect, StatusCode=307].

So please help us out in resolving this issue asap.this is very urgent