JSON parse error

Hi,
I am trying to use connector implemantation for api post request.
My payload : {
“name”:${name},
“city”:${city}
}

@PostMapping(value = “/details”)
public String deta(@RequestBody Details details) {

    Map<String, Object> variables = new HashMap<String, Object>();
    ObjectValue dataValue = Variables.objectValue(details)
    .serializationDataFormat("application/json")
    .create();
    variables.put("Name", details.getName());
    variables.put("City", details.getCity());
    ProcessInstance instance = runtimeService.startProcessInstanceByKey("D1", variables);
    return "Success";
    }

@Getter
@Setter
public class Details {
private String name;
private String city;
}

2020-09-15 15:51:24.798 WARN 9412 — [nio-8083-exec-1] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.http.converter.HttpMssageNotReadableException: JSON parse error: Unrecognized token ‘hari’: was expecting (JSON String, Number, Array, Object or token ‘null’, ‘true’ or ‘false’); nested exception is com.fasterxml.jackson.core.JsonParseException: Unrecognized token ‘hari’: was expecting (JSON String, Number, Array, Object or token ‘null’, ‘true’ or ‘false’)
at [Source: (PushbackInputStream); line: 1, column: 42]]

    Can someone help me out solving this issue?