You can manage your tax forms from your Stripe account dashboard (e.g., download a 1099 tax form if you're a U.S. citizen).
Stripe issues your tax forms. As required by the IRS, the amount listed on your 1099 form reflects the total gross volume that you've processed, and includes things like disputes, refunds, Stripe fees, and Substack fees. It does not include authorization holds or anything where money has not yet been exchanged.
To figure out your net volume (i.e., the amount that you personally earned), you will need to determine your deductions, such as Stripe fees and "Applications fees" (i.e., Substack's fees). More information is available on Stripe's website, including where to find these numbers in your dashboard.