Hello firas.
You need to use it like this:
your-url-goes-here.com/wp-json/posts?type=your-custom-post-type
Change your-url-goes-here.com with your actual URL and your-custom-post-type with your post type.
Example:
amazingwebsite.com/wp-json/posts?type=coins (for example… this is a fake url, of course)
Remember that always after /posts, /users, /media goes a “?” and the next endpoint filter goes with “&”… so, If you can to put the post type at last… goes like this:
amazingwebsite.com/wp-json/posts?filter[s]=Hello!&type=coins
Then, you search all “Hello!” inside custom post type: coins
