credentials admin / admin not working

[sys-lamb]

fly --target=tutorial login --concourse-url=http://127.0.0.1:8080 --username=admin --password=admin
logging in to team 'main'

error: oauth2: cannot fetch token: 401 Unauthorized
Response: {"error":"access_denied","error_description":"Invalid username or password"}

[weyderfs]

try to use fly --target=tutorial login --concourse-url=http://127.0.0.1:8080/ --username=test --password=test