Problem to install

Dear sir,
I can not install skatter 1.4.13 in SketchUp 20.0.363
do you have any idea to fix it?

Thank you in advance

What happens exactly? Any error message?

After completing the install plugin when I open the Sketchup program. It does not have an error message appear
either in the extension manager, I also could not find it
I try to reinstall with Sketchup 2019 too, but it doesn’t work as well
if you have any solution, please sir

Do you see Skatter in the Extensions Manager? (From the Window menu)