401 NOT_AUTHORIZED

I found the reason, remove 'alg' from header, and it works.

Maybe the document should be update.

you are my hero!

Today,I also meeting this problem,I try your method 。But it`s don`t resolve my problem。Help me ,please!

What I do to get my JWT:

I am using a Python Library (authlib) to generate my JWT.

import datetime

from authlib.jose import jwt

def main():
    header = {
        'alg': 'ES256',
        'kid': '##########',
        'typ': 'JWT'
    }

    payload = {
        'iss': '################################',
        'aud': 'appstoreconnect-v1'
        'exp': int(datetime.datetime.now().timestamp()) + 1200 # token good for 20 min, as per https://developer.apple.com/go/?id=api-generating-tokens
    }

    key = open('AuthKey_##########.p8', 'r').read()
    token = jwt.encode(cls.header, cls.payload, key).decode('utf-8')

    print(token)

if __name__ == '__main__':
    main()

I then use that token in a form similar to 'Authorization: Bearer $token' in a GET.