Directly from; ("https://support.mozilla.org/en-US/kb/enable-and-disable-cookies-website-preferences#w_how-do-i-change-cookie-settings")

idk- Try to write a polite email to Mozzilla to ask them to change their Ui

You can inspect cookies and passwords and permissions for the domain in the currently selected tab via these steps:

• click the Control Center 'i' icon at the left end of the location/address bar
• click the arrow to expand the security message
• click "More Information" to open "Tools -> Page Info"
• click "Permissions" to inspect and modify permissions
• click "Security" to inspect and modify cookies and passwords in a standalone window

• click "View Cookies" in "Tools -> Page Info -> Security" to inspect the cookies for the domain in the currently selected tab
• click "View Saved Passwords" in "Tools -> Page Info -> Security" to inspect the passwords for the domain in the currently selected tab