Not proper way to fix the encoding error.

Gzip is not a standard option in Accept-Encoding, but removing 'br' can still fix the issue. However, to avoid using non-modern browsers without gzip support, it may be better to force users to install Brotli. 

This error occurred on my newly installed Python on Windows; there were no issues on my Linux machine.

pinterest-downloader.py

@@ -197,7 +197,7 @@ def get_session(ver_i, proxies, cookie_file):
             'User-Agent': UA,
             'Accept': 'application/json, text/javascript, */*, q=0.01',
             'Accept-Language': 'en-US,en;q=0.5',
-            'Accept-Encoding': 'gzip, deflate, utf-8',
+            'Accept-Encoding': 'gzip, deflate, br',
             'Referer': 'https://www.pinterest.com/',
             'X-Requested-With': 'XMLHttpRequest',
             'X-APP-VERSION': VER[ver_i],