Thats how tesla itself does it (little bags). At least, that is what I saw when I was in there for service a couple weeks ago.
I wondered about this myself, when I first got my car in 2018. (/e shakes cane....) "Back in my day" (lmao) there were not nearly as many teslas as there are now, and model 3s were pretty new so no one really knew what to do with them. I got a lanyard style holder for my keycard, that I keep in my glove compartment.
I dont valet anywhere unless its mandatory (I avoided it with my other vehicles too), but I like to be prepared in case. Now, of course, these cars are basically toyota camry's so any valet would have had to figure out how to ID these cars a long, long (long) time ago.