Update database Mysql

My files are stored on an external hard drive. I threw the file not through the web interface. When entering the web interface there is no file. How can I update my database Mysql?

https://www.c-rieger.de/using-nextclouds-command-line/#zwei

In the command line, I ran

cd /var/www/html/nextcloud
sudo -u www-data php occ files:scan --all

Everything is successful, but there are no files in the web interface.

What’s the mount point of the external drive?

Are the files owned and writable by www-data?

/mnt/usbstorage/Nextcloud my files here

I unplugged my external hard drive from raspberry. Files uploaded through Windows. I used the linux file system Paragon. And then I connected it back. I would like to display the files in the web interface without reinstalling Nextcloud.