Google Business Profile has an API. It covers posts, hours, attributes, questions, media, and a good deal more. It does not cover Products.
There is no public API endpoint for the Products section of a Google Business Profile. Every product tile has to be added, edited, and removed by a human inside the interface. If a vendor tells you they automate it, they are either paying someone to click, or they are not doing it.
Why this is worth knowing
Products is one of the few parts of a profile that shows a picture, a price, and a description directly in search results. For a retailer or a service company with defined packages, it is valuable space. And because it cannot be automated, most competitors leave it empty.
That is the opportunity. It is also the trap, because "we manage your Google profile" from a vendor whose whole model is automation usually means the automatable parts only.
What to ask a vendor
That last one settles it in about ten seconds.
The same gap exists in other corners of the local search stack. Plenty of platforms expose a read API and no write API, so a dashboard can show you a number it cannot actually change. Reading is not managing.
What we do about it
We treat Products as a scheduled human task rather than pretending otherwise. It goes on a calendar, someone does it, and the change is logged. That is less impressive than claiming a robot does it, and it has the advantage of being true.