Hi @Marta1789, after your trip ends, Airbnb asks you to write a review and provide a rating within 14 days. This is the deadline for leaving reviews, after this time it is not possible to write a review (even if you contact Airbnb support, they will not be able to provide you with the option to leave a review).
But I can recommend you to give the feedback about review policy and write your opinion (that the period could be extended to 30 days). There is specilal link "Give us feedback " which you can find on the website and in the App menu.
Kind regards.
Elena.