Where does Bank Name get pulled from when creating an 820 ACH file?

In testing creating the 820 ACH file via Financial Gateway, I am populating the N1*PR and N1*PE fields without issue. However, the N1*RB field keeps coming up as UNKNOWN. Looking at the code in App Package TR_FORMAT.Payment.EDI820Formatter, I can't figure out where it should be pulling that Bank Name (BANK_NAME) field from. Based on how the rest of the file has worked, I think it must be a setup thing somewhere. Where is the Bank Name pulled from? This section of the 820 file looks like the below, with MyCompany and VendorCompany subbed in for the actual values.