Can not see extension

**I am using SketchUp Make 2017 and have down loaded the extension “Uniform Rational B-spline curves”. The manager shows it is enabled. I have reloaded SketchUp. It does not seem to display.

Do you have a curve to start with?

Select an existing nonrational or rational Bezier curve or Uniform Rational B-Spline curve from this tool and use Edit as Rational Uniform B-Spline or Edit Rational Uniform B-Spline respectively in the Right Mouse Button context menu to activate this tool.

I don’t have a spline curve. I tried right clicking an arc.

The tool is specifically for editing splines.
So you need the other tool that creates the splines for this to have anything to work on.
It won’t do anything on a normal arc.

I see. Appriciate your help. Could you suggest one the creates a curve through say 5 point.

Personally I use Fredo’s tools, but the warehouse has several. This is one of them.

I think it’s Fredo’s that has the animator tool that I am interested in also so I shall follow your advice and use one of theirs.