Lost Account Details After Reinstalling Mac OSx

I recently clean-reinstalled Mac OSx Mojave but didn’t realise I had to remove my Sketchup Pro licence beforehand. Now I have reinstalled the app but I am unable to login as I’m unsure about my Sketchup account details. I’ve tried my mail mail email address and another I retrieved from the Keychain, but both are reported as having no account details associated with that email address.

Any suggestions welcome.

So what license are we talking about? Which version of SketchUp?
Your profile indicates SketchUp Free, which is the online modeler. it will require your Trimble ID.
You can set the password if you forgot while logging in.

If you had a Pro license prior to version 2019, You have a ‘classic’ license. The email or Trimble ID is not tied to that license, you would have to add the classic license in the welcome screen.

If you have Time machine, you could try to look for the SketchUp.lic file:
~/Library/Application Support/SketchUp/SketchUp 201x/SketchUp.lic

Open it with a texteditor and look for your serial number.

use that number to retrieve the code: