Hello, Carlson Huang.
Welcome to Microsoft Community!
I noticed that you seem to be setting up a face recognition verification method for the first time. When the camera program is working, I am encountering an error that the camera cannot be opened.
First of all, if this is a brand new device, it shouldn't be giving this error. I think it could be a camera fault. The repercussions of any product quality issue should not be borne by the consumer. So if you haven't owned this device for more than 60 days, I would first encourage you to contact a sales representative for a return or exchange.
If you wish to troubleshoot the issue yourself, you can try what follows.
Incorrect drivers can cause this issue, and you can manually obtain the Surface Laptop 7 driver and firmware installer to troubleshoot any unknown driver failures and maintain device performance:
Download Surface Laptop 7th Edition from Official Microsoft Download Center
If the issue stems from the driver, then the above steps usually work.
If the problem persists, we need to consider the possible impact of an incorrect configuration file. You can refer to the following suggestions to create a new local account for testing and observe if the face recognition feature of Windows Hello works in the new account environment:
Manage user accounts in Windows - Microsoft Support
These are thoughts and troubleshooting suggestions that I can share with you at this time.
Any progress is worth sharing. I am very focused on your experience and respect your thoughts or decisions.
Best Regards.
Leo.L - Microsoft Community Support Specialist