Hello Jintao,
Thanks for the report! On my end the API still appears to be accessible and working as expected–I created a creative at around the time of this email.
Looking at the URL you included in your email, it appears you may have sent an API request to an unintended target. The URL "
google.golang.org/api/realtimebidding/v1" appears to be generated documentation for the Go client library, whereas the URL you would want to use to call Real-time Bidding API's
buyers.creatives.create method is formatted as follows:
```
```
Assuming that I'm understanding correctly then, adjusting the URL should resolve your issue. Feel free to reach out if you have any follow-up questions.
Regards,
Mark