[youtube:tab] Switch continuation to browse API (closes ytdl-org#28289,

closes ytdl-org#28327)

Until further investigation.

youtube_dl/extractor/youtube.py

@@ -2478,34 +2478,44 @@ def _entries(self, tab, identity_token):
         headers = {
             'x-youtube-client-name': '1',
             'x-youtube-client-version': '2.20201112.04.01',
+            'content-type': 'application/json',
         }
         if identity_token:
             headers['x-youtube-identity-token'] = identity_token
 
+        data = {
+            'context': {
+                'client': {
+                    'clientName': 'WEB',
+                    'clientVersion': '2.20201021.03.00',
+                }
+            },
+        }
+
         for page_num in itertools.count(1):
             if not continuation:
                 break
+            data['continuation'] = continuation['continuation']
+            data['clickTracking'] = {
+                'clickTrackingParams': continuation['itct']
+            }
             count = 0
             retries = 3
             while count <= retries:
                 try:
                     # Downloading page may result in intermittent 5xx HTTP error
                     # that is usually worked around with a retry
-                    browse = self._download_json(
-                        'https://www.youtube.com/browse_ajax', None,
-                        'Downloading page %d%s'
-                        % (page_num, ' (retry #%d)' % count if count else ''),
-                        headers=headers, query=continuation)
+                    response = self._download_json(
+                        'https://www.youtube.com/youtubei/v1/browse?key=AIzaSyAO_FJ2SlqU8Q4STEHLGCilw_Y9_11qcW8',
+                        None, 'Downloading page %d%s' % (page_num, ' (retry #%d)' % count if count else ''),
+                        headers=headers, data=json.dumps(data).encode('utf8'))
                     break
                 except ExtractorError as e:
                     if isinstance(e.cause, compat_HTTPError) and e.cause.code in (500, 503):
                         count += 1
                         if count <= retries:
                             continue
                     raise
-            if not browse:
-                break
-            response = try_get(browse, lambda x: x[1]['response'], dict)
             if not response:
                 break