You're not invited to have a strict cancellation policy, it's a selection you make when you're setting up your listing - you can choose between flexible, moderate, strict etc.
It's under booking settings, then policies.
you may find this link useful - it gives all sorts of good advice about creating your listing
thank you for the usefull link, but we have already listed the property and we want to change the policy to stricter one.. how can we manage ? what is the invitation and how we send it ? please check print screen and give us a quote