API MICROSERVICES Certifications Projects are dissaproved all time

All exercises I have tried to commit in the API & MICROSERVICES Certifications projects are disapproved even though I test by myself, and they are right.
For example in the Exercise Tracker:
curl -X POST --data “username=John” https://quirky-delirious-gorilla.glitch.me/api/exercise/new-user
However https://www.freecodecamp.org/learn/apis-and-microservices/apis-and-microservices-projects/exercise-tracker
rejected me.
What’s wrong?