Form data not storing in webflow when using "Action"

I have a form on my website with two fields (first name, email). When filled out, I need it to redirect to a third party website and pre-fill the first name and email on their form.

If I insert the magic link into “Action”, it auto fills the form fields on the other website no problem, but none of the data is collected in webflow.

If I insert the magic link into “Redirect URL”, it collects the form data in webflow, but does not auto fill the fields on the other website.

Is there some sort of work around? I’ve tried some Javascript solutions but im not familiar with javascript so it hasn’t worked for me.

Here is the magic link: Invest in HerdWhistle Technologies Inc. | DealMaker

Here is my site Read-Only: Webflow - HerdWhistle Investors