Then the staff at Getty is hopeless.
This is the same place that thinks the nearly obsolete EPS format is still the gold standard. This is the same place that doesn't actually sell vector art, even though that's what they call it.
See for yourself. Go to their vector art section. Select an image. Any image. Then ask yourself; if these are vector, why are they listed as 300 dpi? Why is there more than one price point? A truly vector image has no resolution. There would only be one "size" to sell as vector is infinitely scalable.
Personally, I wouldn't even work with a company this computer illiterate.
And I just changed the settings on my iPhone 14 Pro to shoot JPEG instead of RAW. Files are named with a .JPG extension (as seen in Image Capture on my Mac so can see the actual file name).

If I copy the file directly from my phone to the desktop, that is the name of the file. It doesn't change to .jpeg, or whatever.
So, what exactly are they complaining about?