Creating a google analytics trigger based on a custom form field for form submissions

Question:
How do I track custom form dropdown field values as part of a form submission that is passed back to google analytics?

Product:
Wix Editor

What are you trying to achieve:
I have a custom form on my website that tracks email leads who land on our site. We ask leads to indicate their company size in this form using a dropdown. I want to create a conversion event I can optimize towards in google ads that is only recorded when these form submissions have a certain company size.

Right now I can track form submissions, I just can’t pass that company size back as part of the lead/submit_form events. Let me know what you folks recommend.

Should I create a custom variable in google analytics? Do I need a custom code snippet using the analytics api? I’ve seen a bunch of mixed answers but nothing clear.

What have you already tried:
I’ve tried looking for it in the data layer and am looking into writing a custom javascript listener (My issue is how I map the custom field value to a google analytics field that doesn’t yet exist and whether tracking should be triggered by the tag or by the header code in Wix)

I figure there has to be a simpler way to do this

I ran into the same issue and got it working by sending the form field data into the data layer first, then using that in a custom GTM trigger. If you’re tracking lots of custom fields or doing this for clients, a website analytics agency might be able to set up a cleaner solution or help automate it across multiple forms.

did anyone end up successfully pushing custom field data into Google Analytics using Google Tag Manager? I’m trying something similar and wondering if a Data Layer push with a unique event name did the trick for anyone here. Thinking about using GTM’s triggers with form field values—just not sure about the best timing or setup.