There are currently 4 ways to earn "cryptos" in the game, One way is through the Drowsy Cash skill you can learn, which grants more cryptos from mini-games. It will also grant you cryptos passively.
The other ways are from playing the mini-games and leveling up contacts. Drowsing contacts also grant Cryptos.
There is currently no way to convert EXP into cryptos, but you can use cryptos to boost EXP gain. You can do that with an item you can purchase and with a skill you can learn.