This evidence is of a fire being present in a photo-Human dwelling place does not answer that question. The European area that is now Spain is believed to have populations of H. antecessor in that time frame which is currently thought to have evolved into H. heidelbergensis which was the likely ancestor to both H. neanderthalensis and later H. sapiens.
The question to me is when and how do anthropologists and paleontologists decide that these predecessors went from obtaining and preserving natural live coals to the ART of creating fire at will as is described in this article. While both acts require mental ability that is beyond that of any other animal now known, the latter is a definite aspect of tool making!
Good question, and it’s difficult to imagine any evidence that could possibly answer that conclusively. As soon as fire was found to be useful, it probably happened. The alternative appears to be, that for 100s of 1000s of years, the earlier hominim types were carrying it from a natural source, and/or keeping it stoked once it was in the desired place.
If you find several, small fire locations repeatedly used, I’d say you have evidence of fire making rather than taking advantage of chance wild fires. Of course, the discovery of such requires good forensic archaeology.