Order Form Custom Code Injection

Hey everybody,

Trying to figure out a way to avoid a 3rd party form to include file upload. I injected HTML into the form, and it looks great. However, after submission, the data isn't included in the form storage locations (email and google drive). I assume the reason that doesn't work is because the form is given a unique id upon creation and that id is what is used to transmit data, making the JS injected AFTER the creation of the form invisible in the data transfer. Any ideas on how to get around this?

Here's the code I've injected into the footer:

<script>
    // If on order-form-page, inject file upload element
    if (document.URL.includes('/order-form-test')) {
        document.querySelector('#textarea-yui_3_17_2_1_1572443434525_3770').insertAdjacentHTML('afterend', '<h3>Please Upload Artwork Here</h3><input type="file" id="myFile"><br><br>');

        document.querySelector("#myFile").setAttribute("accept", ".doc,.jpg,.png,.jpeg,.docx,.pdf,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document");
    };
</script>

Please provide the site url that you have activated the code

Thanks dhayes22