You need to 'show' her to him for a while, first, (I spent several hours doing this). You could have her in a small container (with good visibility) next to his tank. He'll flare and show off.
When you introduce her to him in the actual tank, he might be quite aggressive to her. He'll work on his bubble nest and keep chasing her away. After a while (it might be hours) it's as if a switch is flicked, and she'll nose up to him - she might even nudge him in the side as if to say, "I'm ready!".
They then do this incredible mating, where he rolls her up in his fins and they just drop through the water. She releases her eggs and then stiffens as if dead, but she then recovers. They'll do this a few times.
You then need to get her out; it's not fair to keep her in there as he will become aggressive again.
You then need to remove him once the fry disengage from the water surface (they hang there for a few days), otherwise all your hard work will have been for nothing as he munches on his offspring!