cannot download youtube

Hi, taiyongxuan. 

Welcome to the Apple Support Communities. Being able to download apps is important, so we can understand why you’d want to figure this out. 

To start, learn what to do If you can’t download or update apps on your iPhone or other Apple device.

If the issue persists, or we do not have a correct understanding of the issue, don’t hesitate to reach back out. 

All the best.