I just had to throw out a pot of seedlings that was completely covered with moss.
I've been trying various conditions, they take 4-8 weeks to germinate. Maybe less if you treat at least 24 hours with GA3.
Sown uncovered, same conditions as the parent plants have been grown in: room temperatures with morning sunlight. Media kept very wet - water nearly to the surface of the medium.
What didn't work - bagged under lights at room temperatures. Bagged under lights tropical temperatures (85-90°F days 75-80°F nights). After three months with no germination these batches were changed to the uncovered conditions and they germinated within 6 weeks.