Depending on how you purchased the software in 2019, you will use one of two activation methods:

Search for messages from sketchupmail@sketchup.com sent around your purchase date in 2019.

Understanding SketchUp Pro 2019 Licensing SketchUp Pro 2019 was a pivotal version in the software's history, as it introduced the transition from permanent "Classic" licenses to the modern subscription model. Because this version supports both licensing types, users often look for serial numbers and authorization codes to reactivate their older software.