Extract from the Wikipedia article:

Thereafter, the male will grab the front legs of the female in amplexus, causing the cloaca and the skin of the female to swell.[17] The partners rise from the floor while in amplexus and flip through the water in arcs. The couple will swim around in the water until they have to swim to the surface to breathe. Afterwards, they will swim back down to the bottom of the water. There the male will lay on his back, with the female on top of him on her stomach.[18] During the amplexus, the female’s back is gradually swelled to a puffy condition. The male and female cloacae are brought close together, and many eggs are transferred anteriorly to the female’s swollen dorsal epidermis.

The eggs, each around 6.5 mm in diameter, then become implanted into the female’s dorsal epidermis. During the first day the eggs on the female’s back will sink into the skin and by evening will be set into the back of the female. Two days later, the yolks of most of the eggs are beneath the skin level and only parts of the jelly and outer membranes of the eggs are visible on the backs above. The coverings over the eggs will remain in the wild until the brood emerges.[15] The embryos develop through to the tadpole stage inside these pockets but do not emerge as tadpoles, instead remaining in their chambers until complete development to toadlet stage. The young toads grow a tail during their growth, but these will only be temporary because they will need the tail for inhaling oxygen. After 12 to 20 weeks, the young toads will hatch as small toads, looking identical to their parents. It takes a while for them to grow bigger since they are only 25 mm long when they are born. Once they have emerged from their mother’s back, the toads begin a largely solitary life. After giving birth to the new toads, the mother slowly sheds the thin layer of skin used for birth and can begin the cycle again.[4]

Interested part about the males fighting ritual:

When two males encounter each other during the mating season, there is a possibility that the two males will fight. The toads nearly press their snout to the chest or throat of the other male. During the conflict, both males make single clicks to each other, which resembles the sound that they normally use during breeding. If the toads have eye contact, they make a rapid series of these clicks. This process shows no visible movement of the vocal system. After some time, they will return to swimming, but will never lose contact with one another. One toad swims very closely above the other, touching his rival with only the front limbs. The fight between males may be long-lasting. Eventually, one of the males bites the other male and this is supposed to be the end of their encounter, although they do not always give up the fight. It may happen that the male that loses the battle does not give up and disturbs the breeding pair itself, even during reproduction.[15]

I want to scratch them all out. Ahhh

Fuck this thing right in the ear. I’m not looking!