After checking multiple tutorials I had to take pieces from each of the following to get this to work on my Win10 system:

• https://www.howtogeek.com/165268/how-to-add-open-powershell-here-to-the-context-menu-in-windows/
• https://www.tenforums.com/tutorials/60175-open-powershell-window-here-context-menu-add-windows-10-a.html

Basically it uses the steps from the first article, but under the background path from the second article. Neither article on its own worked for me.

Steps: