Reinstalled PSE 2018 and it says it's now a trial version

I purchased Photoshop Elements 2018 for MAC last year and everything was great until I purchased a new iMac.  I used the time machine backup to restore files and it loaded my PSE, but now I get a pop-up telling me that it's a trial.  I no longer have my box with the serial number, but I registered it with Adobe.

Is there a way to recover this, or am I screwed.  So frustrated, but my fault I didn't put that serial number in a secure location.  I signed into ADOBE but didn't see anywhere that it's listed.  I hope I'm missing something, I don't want to have to upgrade this to 2019.

Thanks for any help you can give me.

Frustrated in Nashville...