Relate camunda webapp to camunda plateform

Hello guys ,
i downloaded camunda plateform , camunda webapps , and camunda UI (open source) and
i have some custumization in camunda webapps ,
now i want to relate the camunda webapps to camunda plateform which it have the engine … because now camunda webapps take the information and api from an url i think , but i want it to retrieve all things from camunda Platform wich is a project ( in a folder) , what i should i modify in camunda webapps POM file to integrate it or what i should modify in camunda plateform to connect it to camunda webapps ,
and thank you very much