Hi
I have lost my QR adopter you know where I can buy them?
Thank you
Contact Zwift support. They may just send you a replacement. You may need to be a bit persistent to get past the chat bot, so prepare yourself for that.
I have been trying to get an answer about this too. I lost mine in a move and need a replacement adaptor. Seems impossible to get an answer. Just want to find out where you can purchase a new one. Should not be this hard. 
I have now emailed. The chat bot is not on point at all. Not even close. Any other suggestions.
The chat bot is a series of hoops you jump through to get to the point where it lets you file a support request. Think of it as a barrier to getting what you need. Keep going until it gives up.