How to factory reset One Plus with a black screen

I dropped my phone. The screen didn’t shatter, but the screen is black.

I can’t do anything including transfer my data. The alarm clock goes off constantly.

How can I stop the alarm? I can’t send the phone to the insurance co. in the mail like this.

I also have confidential work information on the phone that was still open when the phone fell.

I need BIG help!!!