Start Camunda instance from React - reactjs

Question

I am trying to start using camunda.
So far I have created a spring boot service in order to build an api and later use it in my react application to start a process instance. This is my spring boot code :
package com.example.camundaNewTest;
import io.camunda.zeebe.client.ZeebeClient;
import io.camunda.zeebe.client.api.response.ProcessInstanceEvent;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.web.bind.annotation.*;
import java.util.Map;
import static io.camunda.zeebe.client.impl.util.VersionUtil.LOG;
#RestController
public class RestCalls {
#Qualifier("zeebeClientLifecycle")
#Autowired
private ZeebeClient client;
#CrossOrigin(origins = "http://localhost:3000")
#PostMapping("/start")
public void startInstance(#RequestHeader(value="var") String var) {
final ProcessInstanceEvent event =
client
.newCreateInstanceCommand()
.bpmnProcessId("demo")
.latestVersion()
.variables(Map.of("var", var))
.send()
.join();
LOG.info("Started instance for processDefinitionKey='{}', bpmnProcessId='{}', version='{}' with processInstanceKey='{}'",
event.getProcessDefinitionKey(), event.getBpmnProcessId(), event.getVersion(), event.getProcessInstanceKey());
}
}
This is working as expected. Now I want to do this call directly from my react app without a third service (spring). However, I can't find anything useful to achieve this. According to camunda documentation, it uses a grpc call to start the instance. So far, I have found some resources talking about react hooks (https://reactjsexample.com/a-react-hook-which-helps-you-to-deal-with-grpc-apis/) but I cannot make it work. Are there any ideas? Or similar situation that may hint the solution? Thank you!!