How to find 3 words for google map pin please ?

Right-click the pin and click the co-ordinates to copy them to your clipboard

In your web browser address bar, type w3w.co/15 and paste the co-ordinates from the clipboard & press enter

You will get the what3words location of the Google pin

If you are using a Chrome based browser (that includes Edge) you can add the what3words maps extension from here:

https://chrome.google.com/webstore/detail/maps-with-what3words/kjdggbneannapcpmgobggobbnhecfpbh56