Each dragon can participate in pairing both as a male and as a female.
If your dragon participates in the process as a female, then you will get offspring.
If your dragon participates in the process as a male, then you will get money, which the owner of the female will pay for siring.
If you want to get the desired offspring, then in the Market -> Siring section you need to select the dragon (male) you are interested in, then select your dragon (female) and pair them. After that, your dragon will go into the state of "pregnant" and after a while you will have a new dragon. The new dragon obtained in this way will have external characteristics and combat abilities inherited from the parents according to certain rules. Thus, by intelligently selecting pairs of dragons, you can deduce the offspring with the properties that interest you.
If you want to earn money by pairing your dragon, then you should expose your dragon as a male. To do this click on the "pairing" button in the description section of your dragon and set the cost that you want to receive for the services of your pet, and the time during which it will wait for the female. Right after your dragon pared, your game account will receive the amount paid by the owner of the female.