Hi @Luen3
You can manually block the dates by simply clicking on those dates and changing their status to "blocked".
If you want your calendar to automatically be blocked when you get bookings from another site, you can go to the calendar and click the availability tab. Scroll down and find the option "connect to another website". Here you can paste the link for the other site's calendar so that your Airbnb calendar automatically imports the dates that are blocked on the other site.