I've been trying this for 2 years. Grew out 3 males as my female was killing them but this one out grew her and there showing signs of mating at the moment but I haven't cracked it yet.
Here's my male and female
Good luck
I have found the best way to pair up these is to have the males larger than the female and use a divider with a hole large enough for the female but not the male. I put a pot on the male side. Feed heavy and do lots of water changes. Mine love worms and crayfish.