React: onSubmit for embedded form

I have a react application with an embedded form from cognito forms. The script I have below embeds the form in my component. However, I want to add an onSubmit function within the component for that form. I tried to simply add onSubmit to the iframe but that does not do anything.

According to their docs, you are supposed to add a script:

<script>
  Cognito.on('beforeSubmit', function(event) {
    if (event.data.entry.Name.First === 'Bob')
      event.preventDefault();
  });
</script> 

But I have no idea how to implement that in React. I get the error 'Cognito.on' is not a function. Here is the code I have embedding the form:

{indJob &&
    <iframe src={indJob.forms.electrical}></iframe>
    <script src="https://www.cognitoforms.com/f/iframe.js"></script>
}