New Developer Here With Some UTM Questions

Hello, 

I am developing amplitude with my ecommerce website smartbettor.ai. I have currently implemented amplitude to track events using the java script sdk. I track payments with stripe and want to track sign ups. After a successful stripe checkout users are redirected to a registration form. The only way to complete sign up is to complete this registration form so I have our ‘sign up’ event being the submission of this form. 

There are 2 problems with this currently.

1.  
2. Numbers between what stripe says the customer sign ups are and what amplitude is saying are very different. Why would amplitude not be able to track every time this event happens and have significantly less than what stripe says?
3. We want to track utm source. We are starting ad campaigns and want to know what website the user came from. I added these lines which I assumed would track:

   includeUtm: true, // Track UTM parameters

   includeReferrer: true, // Track referrer

   includeGclid: true, // Track Google Click Identifier

   includeFbclid: true // Track Facebook Click Identifier

   });
   
   This is great because we can see the path the user took:

   

   
   
   
   
   However when looking at the data we see EMPTY fields where we want to see data:

   

Any advice helps! Thank you.