Searching Gmail by Star next to email

I've Googled this issue but Gmail Help support page doesn't solve the
problem.

You receive an approved email. You star it.

Now you want to search for only the messages you've starred.

Clicking on the empty box in the upper left above the messages which lists
Starred emails does nothing.

How have you searched gmail by only the Starred emails?

Thank you.

Charles.

Charles Meyer
Charlotte County Public Library
Port Charlotte, FL