Good afternoon Nora YU,
Thank you for contacting Microsoft Advertising Support about your ad delivery query, we are always more than happy to help!
There can be many factors that can affect and prevent your ad from running.
If this occurs, we have a helpful Ad Delivery status that tells you what is preventing your ad from displaying.
You can find the Delivery status of your ads and keywords by hovering over the ellipses on the UI columns.
Below, I have provided a link that has a more in-depth explanation on how to resolve that specific delivery status and where to find the Delivery status: Delivery status (microsoft.com)
I also recommend reviewing these troubleshooting steps listed in the following link if you are unable to identify a cause via Delivery status: Are my ads live? (microsoft.com)
Once you have reviewed the troubleshooting steps above and determined your ads are still inactive.
I would love to investigate further to have a better understanding of how to enable traffic for your ads.
I must first verify your account via phone call and gather some specific account information. Please check your private messages to begin the verification process and move further with this inquiry.
I hope you find this information helpful, and I look forward to your response!
Kind regards,
Christina | Microsoft Advertising Support Specialist | 800-518-5689