W̶o̶r̶k̶s̶,̶ ̶b̶u̶t̶ ̶o̶n̶l̶y̶ ̶i̶f̶ ̶y̶o̶u̶ ̶h̶a̶v̶e̶ ̶G̶o̶o̶g̶l̶e̶ ̶K̶e̶e̶p̶ ̶n̶o̶t̶ ̶o̶p̶e̶n̶,̶ ̶o̶r̶ ̶o̶p̶e̶n̶ ̶i̶n̶ ̶t̶h̶a̶t̶ ̶s̶p̶e̶c̶i̶f̶i̶c̶ ̶w̶i̶n̶d̶o̶w̶.̶ ̶
̶I̶f̶ ̶y̶o̶u̶ ̶h̶a̶v̶e̶ ̶m̶u̶l̶t̶i̶p̶l̶e̶ ̶w̶i̶n̶d̶o̶w̶s̶,̶ ̶a̶n̶d̶ ̶y̶o̶u̶r̶ ̶G̶o̶o̶g̶l̶e̶ ̶K̶e̶e̶p̶ ̶i̶s̶ ̶o̶p̶e̶n̶ ̶i̶n̶ ̶t̶h̶e̶ ̶o̶t̶h̶e̶r̶ ̶w̶i̶n̶d̶o̶w̶ ̶(̶n̶o̶t̶ ̶t̶h̶e̶ ̶a̶c̶t̶i̶v̶e̶ ̶o̶n̶e̶)̶ ̶-̶ ̶i̶t̶ ̶d̶o̶e̶s̶ ̶n̶o̶t̶h̶i̶n̶g̶.̶
Update:
And it was fixed - hence changing the review to 5 stars.

This is a simple extension that does exactly what it says it does.
You get an icon the brings you straight to the window with Google Keep Notes.