Thank you for your interest in BSS extension.
The M2 Frequently Bought Together will get data for Frequently Bought Together List in 3 ways:
_Through the list of Cross-Sells, Up-Sells & Related Products
_Through Frequently Bought Together List: you can add products to this list
_Through the Purchase from Real Data: you can set the period of time for this & the extension will get information from your order grid.
Normally, our extension is tested in default Magento, without other 3-party-extension so we can't guarantee if your ERP sales system is compatible with our extension.
If you have any other queries, please feel free to let us know.