This repository contains an example about how to handle, in the same endpoint, variable model requests in Jackson by using custom deserializers and without polluting our domain classes with annotations and external libraries.
Full post detailed the process available here :
https://redamessoudi.com/jackson-polymorphic-deserialization-free-annotations/
I favor simplified code over production-ready code. Don't consider it as best practices, instead use it to understand the goal of the article.
I consider simple and explainable code as a first step to resolve problems, best practices and design-patterns comes after.