whats the movie where these people live in a small area with almost nothing and they can only open a door once a month or they will get killed but then it opens and everything goes to hell

The movie you are referring to is called "The Purge." In this dystopian horror film series, the story takes place in a near-future America where all crime, including murder, is legal for one night every year. People are forced to stay indoors and secure their homes to survive the night.

thats not it

Apologies for the confusion. The movie you are referring to is "The Platform" (Spanish: El Hoyo). It is a Spanish science fiction-horror film released in 2019. In the movie, people are held in a vertical prison, where food is delivered on a platform that travels between floors. Each level receives less and less food, leading to a desperate struggle for survival. The platform only stops on each level once a month, and chaos ensues when it reaches the lower levels.

nope not it

Apologies for the misunderstanding once again. Would you be able to provide any additional details or plot points that could help me identify the correct movie?