All positions created by employers to post to school talent communities must first be reviewed by the school's career center office. When you create a job, you will see it in "submit" status. The school's career center then receives a notification to publish the position.
Their internal workflow for review and publishing process can vary from hourly, daily to weekly. If you are eager and looking for immediate action, you can always reach out to the school directly to check on the status of your position.
Once your position is published by the school, their talent community can then search your position and apply!