This is Elias from Shopify Support. Thanks for reaching out.
I understand you're looking for your 1099-K tax form. If you're using Shopify Payments and your store meets the criterias for tax reporting in the US, you can download the 1099-K form directly from within your admin ('Settings > Payments > View Payouts > Export'). In the United States, you are required to submit a 1099-K form to the IRS if you meet either of the following criteria:
On the other hand, if you're using a third-party payment gateway, you'll need to check with your payment gateway for these tax documents.
Just to confirm, are you using Shopify Payments on your store? Also, does your store meet the criteria for a 1099-K form?