Okay, this is very dated, but here's the concept for summarizing the Farmer's Market as one sales receipt:

https://www.youtube.com/watch?v=NxYliKN0fxE

If you are summarizing, you want a named item that is reportable By Vendor. Or, you could use each Vendor Name as Customer (that's a lot more data entry) and generic items, if you need that level of reporting in QBO. In other words, you either report by Item or by Sale. Or you don't need that level of detail in QBO at all and can generically summarize by Sales Date. The points would be, don't double-track something (because who has time for that) and you can't report something you don't track. It also matters if you use QBO for the built-in sales tax functionality or do it outside and just need reporting.

You don't have to map or connect things; it isn't always the easiest way to get what you need.That's why Michelle shows a POS summary concept (Z-out). It can be X-out, too. It's just a summary tool that's better than JE.

I can't speak to the specifics of that software mapping, but many of my clients are the programmers of those types of integrated tools you are trying to use (I'm their QuickBooks expert and have a programming background) and other clients are Pro Advisors (I somehow became expert at IL sales taxes for one of them). If using Items for each vendor, then you will need to create Taxable and Nontaxable "generic sales" per vendor, at a minimum. You're also going to need discount (or negative value) items, for instance, such as one for Fees your grange hall keeps.

You also need their names as Vendor Names if you are using QBO for issuing 1099, and for the payments to them.

I would track the Square/cc terminal fee as a typical operating expense. You won't "bill" them for the sales tax or fees. It's going to be accounted for in the net you pay them. If you are not using the QBO sales tax function, then this simply is another item, such as:

Taxable Sales <== puts that tax amount into liability, sales into liability

Nontaxable Sales <== sales into liability

You send Tax liability to tax agency

You pay the Vendor from Sales liability:

Sales liability Gross for that vendor, that market date

Grange Market fee as a Negative value (credits income) posting to Revenue

Square fee recapture also is Negative (credits income) to Revenue (because Square will report it on 1099-K)

= net check to vendor

You often can assign numbers to vendors as part of your payment terminals, like Department # or Sales Register, so it depends on how many vendors you get, I suppose, as to if that is crazy or not.

I hope this review helps. I like to describe, "If you can map up, you can set it up." It might not be exactly what you need, but it gives you some ideas of how to use the tools.

You should still be able to sign in at the QB help with your sign in used here, so try a different browser. I use FF with Intuit, not Chrome, for example.