You can get the password to Myza's Oasis by playing a trading mini-game with the brokers in the market. To begin, you'll need to buy the item sold by Xy'darid — the broker found near the door to Myza's Oasis. The item he sells is random, and you'll need to take it to the appropriate broker in the market. For example, if Xy'darid sells you Cheap Spices, you'll need to take them to the Exotic Spice Merchant and drop them in the circle with the extra action button. After dropping the spices, the NPC will give you a different item that needs to be taken to the next broker. After doing this three times, the last broker will provide you with a two-word password to enter the Oasis!