Mark Sando wrote:I tried if the input is just one Request, it'd work. The problem only happens when the endpoint accepts array
Are you saying this is what works for you?
If so, the problem is not that the endpoint is accepting a List (not an array), it's that you're
returning a List.
See if anything in this article helps you:
https://www.baeldung.com/spring-resttemplate-json-list