How do I grant access in Files and Folders in Catalina for Chrome?

I found a workaround by triggering Chrome to add my Documents folder to Security and Privacy:

Initially, Chrome had no access granted in System Preferences -> Security & Privacy -> Privacy tab -> 'Files and Folders', nor in 'Full Disk Access'.

I have an HTML file 'index.html' in my Documents folder.

1. Open a Terminal and run the command:

   open ~/Documents/index.html

2. Chrome is my default browser, hence tries to open the HTML file

3. Chrome displays the following dialog box:

4. After granting permissions and opening the file, we can see in System Preferences that Chrome now has access to Documents.
   In addition, my web page with the RFC1867 'Browse...' file upload button now works as expected.