From Firearms Policy Coalition:

On September 18, 2019, a purported “idea” document reportedly being circulated among Republican senators and congressmen was leaked to the media. The document, entitled “Idea for New Unlicensed-Commercial-Sale Background Checks”, is both frighteningly vague and callous in its disregard for the Second and Fourth Amendments, as well as the federalist principles that animate the Commerce Clause.
The document suggests that “many commercial sales are conducted outside of FFLs without any background check or record-keeping requirements.” This is either incorrect or uses a definition of “commercial sale” beyond the scope of common understanding. Present law requires anyone “engaged in the business” of selling firearms to acquire a Federal Firearms License. Incidental, intrastate transactions between private individuals are regulated by the states.