I’m neither one of CA’s apologists nor even Catholic, but this website seems like a good explanation, or at least a good place to start:
Abraham, at least, is recorded as receiving his camels from the Pharaoh, meaning his camels came from Egypt, and it is entirely possible that those camels might have been around in the days of his sons and grandsons.
This quote, for example:
A lot of argument has been focused on Genesis 12:16, against its mention of camels, not ordinarily accepted as domesticated until much later in the second millennium B.C… But HamiltonF7 cites an Alalakh text (18th century B.C.) with ration lists including that of “one (measure of) fodder - camel”, the very fact of feeding it seems to imply its domestication or use as a pack animal. Camel bones were also excavated at Mari in an early house possibly dating back to c.2400 B.C… An 18th century B.C. Byblos relief depicts a kneeling camel further suggesting its domestication and use as a beast of burden. The above references seem to imply that the mention of camels in Genesis is not just anachronistic.
This site also discusses camels in the Levant. thebereancall.org/content/genesis-camels
These sites might also be useful: christianthinktank.com/qnocamel.html and pulpithelps.com/www/docs/988-5459
None of these are Catholic sites, though, but knowledge can still be gleaned from them. I’ll leave CA’s professional apologists to provide better answers.
This appears to be a regurgitation of an old accusation levied against Christianity (and perhaps Judaism).