Not necessarily. Just because it's said to be based on a true story doesn't mean it's a 100% factual retelling. Maybe it took the basic concept from reality and built a fictional story around it.
Trapped is not based on a true story. It's a work of fiction that brings a unique and imaginative tale to the screen, separate from any real-life incidents.
Yes, it is. There are real - life events that inspired the 'Trapped Alex Cooper' story. It often takes real situations, people's experiences, and then fictionalizes them to some extent for the sake of creating an engaging narrative.