@HaidarBhatti said:

I am struggling to get the cast and crew for a selected movie, please some one help me with it.

If you wish to receive Cast & Crew data

1 This is a basic API Request for a Movies and TV Show
Movies - See here: https://developers.themoviedb.org/3/movies/get-movie-details
Movies - Example: https://api.themoviedb.org/3/movie/550?api_key=THE_KEY&language=en-US
TV Show - See here; https://developers.themoviedb.org/3/tv/get-tv-details
TV Show - Example: https://api.themoviedb.org/3/tv/1418?api_key=THE_KEY&language=en-US

2 If you want to receive the cast & crew in response, use the &append_to_response= feature with the credits parameter.
For TV credits it only provides for the last season. For all seasons aggregate_credits should be used.
See here; https://developers.themoviedb.org/3/getting-started/append-to-response
Movies - Example: https://api.themoviedb.org/3/movie/550?api_key=THE_KEY&language=en-US&append_to_response=credits
TV Show Credits - Example: https://api.themoviedb.org/3/tv/1418?api_key=THE_KEY&language=en-US&append_to_response=credits
TV Show Aggregate Credits - Example: https://api.themoviedb.org/3/tv/1418?api_key=THE_KEY&language=en-US&append_to_response=aggregate_credits

3 Or do the API Request only from Cast & Crew.
Movies - See here: https://developers.themoviedb.org/3/movies/get-movie-credits
Movies - Example: https://api.themoviedb.org/3/movie/550/credits?api_key=THE_KEY&language=en-US
TV Show - See here: https://developers.themoviedb.org/3/tv/get-tv-credits
TV Show - Example: https://api.themoviedb.org/3/tv/1418/credits?api_key=THE_KEY&language=en-US
TV Show - See here: https://developers.themoviedb.org/3/tv/get-tv-aggregate-credits
TV Show - Example: https://api.themoviedb.org/3/tv/1418/aggregate_credits?api_key=THE_KEY&language=en-US