I just recently received my serial number and auth code for Sketchup Pro. (I am in a K-12 organization and we applied for a grant through TCEA and this is how the serial number and auth code were provided to me.
if your e-mail address matches their database to the serial and you maintenance is up to speed you should then be receiving the new serial within minutes, it literally took me less than 10 minutes from starting the download link, requesting the new serial, installing and activating to be up and running in SU2019
Sketchup 2019 And Authorization Code Serial Key And AuthorizationSketchup 2019 And Authorization Code Mac OS X VersionYou can tell by looking at the first letter of the serial number. 1e1e36bf2d