Alien bettas would appear to be a hybrid, though no-one knows from which species. Since they are reported to be somewhat agressive with males fighting to the death I would treat them as though they were betta splendens.
Betta splendens don't choose their mates, a male will mate with any female which is ready. If a female isn't ready to mate, he will chase her out of his territory; once a male has mated with a female, he'll chase her away. But in a tank, she can't get away. That's why males and females should only be kept together while actually spawning, and to breed bettas you need a male tank, a female tank and a spawning/fry rearing tank. Then a lot of jars for when the male fry start fighting.
Betta splendens don't choose their mates, a male will mate with any female which is ready. If a female isn't ready to mate, he will chase her out of his territory; once a male has mated with a female, he'll chase her away. But in a tank, she can't get away. That's why males and females should only be kept together while actually spawning, and to breed bettas you need a male tank, a female tank and a spawning/fry rearing tank. Then a lot of jars for when the male fry start fighting.