Don this article is about church services not a discussion of transubstantion. As we both know that was a doctrine that all church fathers did not have agreement on. This quote does show that the early church had no mass and no “sacrifice” Note no priest , no mass. The pastor was called the” president”. Later the church called the pastors “clerks”.
Since Justin Martyr devoted a chapter of his Apology to the matter, and placed it in sequence with what the service was, he certainly believed it was an integral part of the service.
The author of the OP purports to "get back to the ancient church." He gets back to something; but it's not to the church that Justin Martyr was writing about.