@subhashree801 said:
how to get id
how to get collection id in
https://api.themoviedb.org/3/collection/{collection_id}?api_key=<>&language=en-US

The ID of a collection is in the URL of the Collection itself.
Example with Star Wars Collection
https://www.themoviedb.org/collection/10
In this case the ID is 10.

Then search for the collection you want
https://www.themoviedb.org/search/collection?query=star+wars
Check the menu on the left for the option Collections
Click on that option.
You will see the list of possible Collections.
Click on the one you are looking for.
And so you will arrive at the Collection page whose URL you will see the ID.

I think this subject should be in API Support.
So I'm going to move this conversation to API Support.

This was unclear to me too as I'm getting started today.