Owlfiles for Android has built-in Web and FTP Servers which can help us with file transfer between our computer and mobile phone. You can switch to the More tab in Owlfiles app, then click Built-in Servers in Toolbox section, and start the FTP and Web servers from there. See this file sharing between Android and PC using Owlfiles guide for more details.
Sometimes you may run into the error when Owlfiles for web trying to retrieve content from your Android mobile: error: Failed retrieving contents of “/”.

In this case, you need to change the path or root directory of the web server in Owlfiles app on the phone. Open the Built-in Servers in Owlfiles manager app. Click the edit icon after the path.

Then pick a location as the root folder for the web server and FTP server.

If you like to set the main storage as the server root, tap Main Storage, then tap Save button. Now go to Owlfiles for web on your desktop browser, refresh the page, the retrieving content error should disappear.