I believe you are entering the data from your 1099-SA. In this
case, the "Payer" is the HSA administrator, i.e., the financial
institution that provided the debit card you are using to pay for medical
expenses.
Look
closely at the 1099-SA and you'll see that it says, "Trustee's/Payer's".
The Payer's federal ID number is in the box labelled "PAYER'S TIN" (Tax Identification Number).
Note that you are the Recipient.
