and linked to a specific purchase [1, 3]. Sharing or using public codes often leads to "Invalid License" errors because those keys have likely been blocked by Trimble [2].
you used for the original purchase so I can help you find the recovery link? Sketchup Pro 2016 License Key And Authorization Number
SketchUp has moved to a subscription model. If you need the latest Pro features, checking their current plans is the only way to get a guaranteed working license [1, 2]. Do you still have the email address and linked to a specific purchase [1, 3]