Question: App.jsx

```
import * as React from 'react';
import * as ReactDOM from 'react-dom';

function render() {
    ReactDOM.render(<h2>Hello from React!</h2>, document.body);
}

render();

```

So, right now my friend made a React website that I have to try to port over to an Electron App that I got off of the team's Github. However, when I change the code into this:

App.jsx

```
import * as React from 'react';
import * as ReactDOM from 'react-dom';
import App from './App';

function render() {
    ReactDOM.render(<h1>Goodbye</h1>, document.body);
}

render();

```

Nothing changes at all. All that pops up is the "Hello from React!" from earlier. I search throughout all my code files for any other instances of "Hello from React!" with vscode, but I do not see any. Does anyone know why this is happening and what I can do to fix it?

Answer: 
Ok, so the answer was adding this environment variable :

```
JAVA_OPTS_APPEND=-javaagent:{{path_to_elastic_apm_agent}}

```

this command allows you to launch your java application with options.
The Java agent allows multiple ways to configure it, one of which are command line system properties. Others include packaging an `elasticapm.properties` resource file or setting environment variables.

[Check out the docs](https://www.elastic.co/guide/en/apm/agent/java/current/configuration.html). Small excerpt:

> 
> * **Properties file**: The `elasticapm.properties` file is located in the same folder as the agent jar, or provided through the `config_file` option. dynamic config.
> * **Environment variables**: All configuration keys are in uppercase and prefixed with `ELASTIC_APM_`.
> 
> 
> 

Different option sources have different priority and precedence.

To attach the agent to a running JVM process (from within your application), you can use the [API to self-attach](https://www.elastic.co/guide/en/apm/agent/java/master/setup-attach-api.html#setup-attach-api-configuration).