"Trigger a new Build by Project (preview)" returns 200, but the created build does not run

I have tried this API and 200 returned.

Although the jobs were created, the job statuses were ‘Not Run’ while “Only build pull requests” option in advanced settings was on.
Then, I turned off “Only build pull requests” option, and the job began to work.

This option must be turned off to use this API ?

Hi Hira and welcome!

With Only build pull requests enabled, only jobs created as part of a PR web hook from GitHub or BitBucket will run. Requesting a build via the API will not override that.