Problems with the Pagination using HTTPS in Node.JS

    // store streams in the array
    streams = streams.concat(resp.data);

Will put all the streams into the streams array

But if you only want the total viewers.

var total_viewers = 0;

function getStreams(cursor) {
    // snip do request
    resp.data.forEach(stream => {
        total_viewers += stream.viewer_count
    });
    // snip do paginate
}

100 per page the code checks for a cursor if it has a cursor it self calls the getStreams with the cursor

let streams = []; is hoisted outside the function as a global so would collect all streams into that array. Each call merging the results from the call into that array