The location for "Send Feedback" varies depending on which screen you are viewing.
On your "Home" screen where you view your Stream, there is a "gear" icon in the upper right corner of your Stream. The drop-down menu will display the link to "Send Feedback."
On your "Profile" tab, the profile image covers up the space where the "gear" icon would appear, so the option is a text link that is found below the profile image. You may have to scroll down to find it.
I normally use Chrome browser. I used to use Firefox with NoScript, so I took a look and this is what I found.
I had to allow [google.com] in order to access the drop-down menu from the Gear icon. However, this alone, will not allow activation of the "Send Feedback" tool.