Thanks to you folks, I was able to figure out how to integrate gravity forms with stripe so that people could input their desired values for a custom checkout. However, I'm now facing two issues!
The stripe checkout only shows the name of the service and a total price. It does not say the number of units (in my case "words") that the customer has placed an order for. How do I do that?
Right now, whenever anyone fills out a form to go to checkout, an email is generated that shows how many words the customer selected, but it doesn't show any email, name of customer, or any detail. If the customer was to change their mind and go away, I would have no idea how to contact them again. How do I change that?
Your help, as always, will be appreciated.

I assume you are asking all the relevant customer info on your form? If so, then you can find all that data in Stripe > Entries
To send that data to Stripe, you need to include it in the “Stripe Feed” metadata (under the “Other Settings” heading) in the Stripe settings in your form.