@Katrina149 Both the guests and you don't cancel- it's either a guest cancellation or a host cancellation. This was explained to you in answer to your previous post about this situation.
There is no "address" to send your documentation to. You have to contact Airbnb through the messaging system (go to Help, then scroll down until you get to the "contact us"), explain what the issue is, that it was a cancellation that falls under the extenuating circumstances policy, and submit your documentation through the system.