I have installed JS Rational Bezier Curve extension.
The extension manager shows it as enabled.
When I go to the extensions pull down menu on the main page it does not appear.
I have reinstalled, and tried restarting Sketchup, but it still does not show.
You may be misunderstanding what the extension does, it is a tool to edit bezier curves that have already been created. It doesn’t draw bezier curves, you first need to use the bezier curve tool then access it through the context menu as @DaveR has shown.
Ah! You are right. I misunderstood what the extension does.
The Sketchup Bezier tool does not show up in the extensions pull down either. But the other plug in I used does.
Should I start another post with the correct title?