Forms API external

Hi.
I have a Rest API using Spring Boot. Now, i need to make a Camunda project that have a form, and when i put at this form an ID, i have to get back all the information that i have in my Spring Boot API.

Example:
I Have in my rest API:
String name = Tavares;
int id = 1;

when i call back my api in my camunda project, when i put at the form ID customer, the id 1, I have to get back name = Tavares.

I am new at Spring boot and Camunda.
How can i have an step by step of this ?
Sorry for my bad explication and my bad english, thanks