Hello @Michał71
I'm afraid to say that this is all too common and these scammers target new hosts in particular and yes you do not want anything to do with this person!
There are many stories like these and at the moment requests for videos are common especially coming from China
You will have received this request through an enquiry so your only job is to answer within the 24 hour window and you can use the refuse/deny button and indicate to Airbnb that this person is asking you to go outside of the platform. You can also flag this person in the message stream where they sent you their coded telephone number by using either the three dots or a flag.
All the best
Joëlle