There is nothing to panic about the unexpected loss of booking value due to the collapsing uncertain plans to your travel dates. Although, you need to cancel the flights within 24 hours of booking or on the same day of reservations. This is applicable for those customers who have made the reservation via the official website Ryanair.com.

As per Ryanair Cancellation Policy, one is liable to cancel the flight without any penalty within 28 days in advance of the departure date. And with this, one would have the ease of seeking the refund for the canceled flights within the restricted hours.

Furthermore, if someone cancels the flight beyond the restricted hours due to serious issues such as serious illness or death of someone, the airline does not charge any fee. But customers can seek a full refund for the canceled flight. 

Source: https://www.4yo.us/blogs/25231/Can-I-Cancel-My-Booking-on-Ryanair-Airlines-on-the