How to add custom rest endpoint and deployed in standalone camunda platform as jar file?

I’m running Camunda Platform Run as a standalone application. I know how to develop plugin and deployed as a jar in the userlib in camunda.

Now, I would like to develop a plugin (exportable as a jar) which have custom rest point i.e my defined end points and my defined business logic. Let’s say rest point will be like - “/api/custom/test”.

I build plugin with Spring boot and also add an endpoint. Then I deployed as a jar in userlib directory and then run camunda. But, this didn’t enable my endpoint. If I point to http://localhost:8080/api/custom/test from Postman, it shows error. How can I solve this? Please help me the way of building this. Thanks.