It would be interesting to know what your ultimate objective is. The QMS API is not relevant to your apparent goal. It is for managing documents and platform, not the data in those documents. You'd need to use QVPX interface to interact with the front end, and that is not well documented!
If you want to extract all data from the QVW, then modify the script to store each table as CSV, or binary load the document and extract all tables to CSV. If you binary load the QVW document into Qlik Sense then you'll have access to Qlik Sense APIs which do provide a programmatic interface to the data in the document. You could also consider a 3rd party interface to Sense such as https://www.ipc-global.com/amp/inprocess-odbc
We have a dashboard developed on QV and other team would like to access the dashboard or fetch the data out of it but we can't provide them access to the Dashboard which means they can't access through the Qlikview access point.
My Question is Can we use an QMS API in order for them to get the access to the Dashboard?.
Ultimate goal is to provide them the data using any method.
Programmatic interaction with the document using OCX/OLE Automation methods is possible with a qvp connection (4747/tcp) directly to the QlikView Server or proxied via the Web Tier, but if you trust someone enough to provide them with programmatic access then why don't you trust them to access the Portal?
What are those 'foreign' users going to do with the data that they extract? How are they going to visualize it? Why not use QlikView Publisher to upload the reloaded document to Qlik SaaS and provide the authenticated users with consumer-access to it there?