HI Linda
I am in the same position. I had to cancel due to central heating boiler breaking down.
Have since had boiler replaced and need to send documentation. Airbnb do not make it
clear how to send documents. I have had a message telling me to send by chat, but can't get on to Chat. Neither did they make it clear that you only have 7 days to submit documents, which is
ridiculous.
I find airbnb policy of treating Hosts as the enemy that need to be punished rather annoying.
I have contacted airbnb and am waiting for them to get back to me. If they give me the necessary information I will let you know.