401 Unauthorized App Store Connect API

I'm getting the following error: Provide a properly configured and signed bearer token, and make sure that it has not expired. Learn more about Generating Tokens for API Requests https://developer.apple.com/go/?id=api-generating-tokens

I am using the correct key files and I have assigned the Admin permission. Any help would be greatly appreciated

import requests
import datetime
from authlib.jose import jwt

app = Flask(__name__)

# App Store Connect API information
KEY_ID = 'XXXXXXXXX'
ISSUER_ID = 'XXXXX-XXXXX-XXXX-XXXX-XXXXXXXX'
KEY_FILE = 'AuthKey_XXXXXXX.p8'
APP_ID = '12345678'  # App Store Connect application ID


def generate_jwt_token():
    """ Generate JWT token using authlib.jose """
    header = {
        'alg': 'ES256',
        'kid': KEY_ID,
        'typ': 'JWT'
    }
    payload = {
        'iss': ISSUER_ID,
        'aud': 'appstoreconnect-v1',
        'exp': int(datetime.datetime.utcnow().timestamp()) + 1200  # token good for 20 min
    }
    with open(KEY_FILE, 'r') as key_file:
        key = key_file.read()
    token = jwt.encode(header, payload, key)
    return token.decode('utf-8')  # Ensure the token is a string


@app.route('/latest-build')
def latest_build():
    token = generate_jwt_token()
    headers = {
        'Authorization': f'Bearer {token}',
        'Content-Type': 'application/json'
    }
    response = requests.get(
        f'https://api.appstoreconnect.apple.com/v1/builds?filter[app]={APP_ID}&limit=1&sort=-uploadedDate',
        headers=headers
    )
    
    if response.status_code != 200:
        return jsonify({
            'error': 'Failed to fetch data from API',
            'status_code': response.status_code,
            'response': response.json()
        })
    
    build_data = response.json()
    try:
        latest_build_version = build_data['data'][0]['attributes']['version']
        return jsonify({'latest_build_version': latest_build_version})
    except KeyError as e:
        return jsonify({
            'error': 'KeyError accessing response data',
            'details': str(e),
            'response': build_data
        })

if __name__ == '__main__':
    app.run(debug=True)