When is the cancellation for @Mila16?
As a host BNB takes it very seriously if you cancel a reservation (see information on their website). You will be penalised financially, the dates will be blocked and you won't be able to get superhost status for a year.
However if there are extenuating circumstances - serious illness/death within the family/unexpected repairs to the house for example water damage, they will consider this.
We are a forum of hosts so can't help you with this. I would suggest you call BNB or contact them via social media if you don't have the number use the search function at the top of any forum for 'Contact BNB' and you will see hundreds of answers detailing contact numbers