How to see changes in Data directory on ownCloud 9.x

Hello, I am Japanese ownCloud user. I am not good at English, so there may be unnatural points.

First of all, I would like to see changes in the Data directory from ownCloud 9.x.

I built a system like Gyazo with my server. However, we do not implement the Web interface, so we would like to use ownCloud to delete and share files.

The first thing to think about is to set a symbolic link in Gyazo's upload directory and ownCloud's /data/user/files/ directory.
The method using the symbolic link was effective on the previous ownCloud. However, it seems prohibited in ownCloud 9.x.

Next, I thought about how to make the directory on ownCloud itself a Gyazo upload directory.
However, we noticed that change of directory which is not operation of ownCloud needs to use the following command every time.

"Sudo -u nginx /var/www/html/owncloud/occ file: scan user"

In this state, you can not browse files quickly.

Is there any solution? Or is ownCloud not suitable for my purpose of use?
Please answer. Thank you.

If you need to modify/read files directly without the owncloud-interface (webdav), you can use any directory on your server and use the external storage feature. This directory needs to be accessible for your webserver user (would bewww-data in debian/ubuntu):

I did not know how to do it. I thank you for your help.
Thank you!