Routing API calls in grafana panel plugin

I am building a grafana panel plugin. I have a backend (not grafana backend) runnning at port 8080 and I want to fetch some data from it. Something like the code below

async function fetchAgents(): Promise<string[]> {
  try {
    const url = '/api/agents';
    const response = await getBackendSrv().get<string[]>(url);
    return response;
  } catch (error) {
    console.error('Failed to fetch agents:', error);
    if (error instanceof Error) {
      throw new Error(error.message || 'Failed to fetch agents');
    } else {
      throw new Error('Failed to fetch agents');
    }
  }
}

Now I want to route this. I thought you can rout by specifying routes in plugin.json like

"routes": [
    {
      "path": "/api/agents",
      "url": "http://backend-app:8080/api/agents"
    },
    {
      "path": "/api/set_agent",
      "url": "http://backend-app:8080/api/set_agent"
    }
]

I am not sure if this is enough or no? And what endpoint should I make the call to fetch the data. I am making call at the endpoint below but there is no response.

const url = '/api/plugins/faib-dynotrace-panel/resources/api/agents';
const response = await getBackendSrv().get<string[]>(url);

Can someone explain how can I route this correctly or routing is possible at all? I am very grateful for any help.