Add description to the Attachments field for "Submit a request" form

I suspect the code posted in 2020 is no longer valid. The div listed is not where this text field lives, at least not for me. 

@dave12 No, I'm referring to the code in the comments on this article, for example: https://support.zendesk.com/hc/en-us/community/posts/4409515328538/comments/4409510181018
I have confirmed that jQuery is present in my document_head.hbs . 

Here's a screenshot showing that the div id for "upload-dropzone" closes before the attachment text code even appears, which is why it doesn't work: 


I just haven't had a chance to figure out how to rewrite the JS to reference this class instead of the div ID. 

Is it possible to either have multiple attachment fields or have the caption change based on which ticket form is being used?

I am trying to check for form and a field drop down option is picked. And if those two options are picked then changes the text.

Here has what i have come up with

 if(window.location.href.indexOf("123412") > -1 && $('.form-field.request_custom_fields_112313.val() = "Eligibility Letter"') {
 $('div#upload-dropzone').parent().find('label').text('Attach copy of Letter (Required)')
 }

How can we change the description text based on the drop-down values we select? Is it possible to conditionally change the description at the bottom of attachment field?