Before 2018, SketchUp Pro sold . You paid a one-time fee (usually around $695), and they gave you a "License Key" and "Authorization Number." You typed those numbers into the installer, and the software unlocked forever. This is why searches for older versions (SketchUp 2015, 2016, 2017) sometimes yield results.
To authorize SketchUp 2020 using a Classic License, you must have your unique Serial Number Authorization Code Sketchup 2020 License Key And Authorization Number
Enter the registered email address associated with the purchase. Before 2018, SketchUp Pro sold