Which license goes with which website?

Hi, this is driving me CRAZY. Hoping someone can help…

I purchased many themes from ThemeForest and many times, the same one over and over again. HOW ON EARTH do I figure out WHICH one was installed on WHICH website. One of my clients needs support on one of the themes. I go into all 4 of them that I purchased, I see the license #, and purchase date, but how do I know WHICH ONE I installed on WHICH website? It takes me forever to try and figure that out, sometimes by dates installed, etc. And when I go into the theme in WP ADMIN there is NO PLACE there either to tell. So when I try to contact support, I have NO CLUE WHICH License # to give them??? This is VERY FRUSTRATING! Please tell me how I can solve this. Thank you so much!

You will need to note these purchases ( Purchase code XXX for website XXX ) on your end.
There’s no easy way.