Fintech Experts: How is this company doing this?

The company's name (no joke) is "Fintech" (fintech.com). They are the major player in processing alcohol-related payments; i.e., alcohol distributor A uploads an invoice for a few kegs retailer B bought, and Fintech processes the payment for them. They process 33M alcohol invoices a year.

I can't figure out how they are doing it. They refer everywhere to EFTs which, to my understanding, is ambiguous. Parts of their service agreement (e.g., [1]) talk about ACH, but their marketing (see example below [2]) states very explicitly that the funds don't go through them, it goes straight from Retailer's account to Distributor's account, which I didn't think was possible with ACH (for a third party to initiate an ACH between two other parties). It seems unlikely to be wire because they offer the service for free and wires are expensive.

A competitor, iControl, which I assume is using the same process because Fintech sued them for stealing IP, claims that "Our special banking arrangements and transaction volume allows funds to immediately clear a distributor’s bank account, same as a wire, but without the banks charging the distributor a fee for receiving a wire." [3] Wtf?

What are they doing?? Thanks everyone, I really just can't figure it out.

[1] https://test.fintech.net/fintech-electronic-services-disclosure.asp?Type=Retailer

[2] "Through EFT, each invoice payment is made automatically with funds moved directly from the retailer’s account to the distributors through the Federal Reserve. The distributor uploads an invoice, and the exact invoice amount is paid on the due date listed on the invoice without Fintech ever taking title of the funds." https://fintech.com/blog/touch-free-alcohol-invoice-payment-options-what-retailers-need-to-know-about-escrow-ach-and-eft/

[3] https://www.icontroldata.net/blog/how-eft-payment-processing-with-icontrol-can-improve-your-business