VBA to time stamp cells whose values are derived from a data validation dropdown list

Hello!
I have searched the web for an answer with absolutely no luck. I am looking for a code I can put in that will time stamp my "Time Seen" column (column H) when and an option in my drop down list "Seen By" (column G) is chosen.

I currently use a code (attached) that time stamps my "Check In" column (column A) when a name is put into the "Full name" column (column B). This code does not work when I select a dropdown option vs the manual input that I do for names