In SketchUp 2021, open Window > Extension Warehouse , search , and click the red "Install" button. This automatically handles version compatibility. You will still need to purchase a license afterward.
Includes tools for filleting edges, extending, chamfering, and creating arrays. How to Download and Install To get 1001bit Pro for SketchUp 2021, follow these steps: Download Plugin 1001bit Pro For Sketchup 2021