The URL you get in contentLocationUri has a limited lifetime (signed signature/token with limited duration for its validity).
The document/file is made available on AWS and I see that the url contains X-Amz-Expires=20. Which means that you likely have 20 seconds to start the download of the file.
After it expires, you can request /api/v2/contentmanagement/documents/{documentId}/content endpoint again, and it will give you a new url (new signature/token valid for next 20 seconds).
From what I understand (I have just run the query with inline and attachment):
With inline, the request to the contentLocationUri returns HTML (document data embedded in html/body elements).
With attachment, it returns the document data.
"To load the file on a html page should i use "inline"?"
I would say both would work - it just depends what you do with the contentLocationUri you get in your web page/javascript.
If you want to display the document in a new tab, with no special/additional javascript code or html formatting, or in an iframe, you could indeed use inline and it will give you an HTML page you can display directly/as is.