You can send caravans from the Trading Oasis located in the Sands.
 
You need to complete the following steps in order to be able to send caravans:
- restore the Oasis
- restore the Trader's Tent
- upgrade the Trader's Tent to level 2
- restore the Jeweller's Stall (complete the Total Recall quest)
- upgrade the Oasis to the Trading Oasis (complete the Desert Paradise quest)
 
After completing the "Desert Paradise", you will unlock the Trading Oasis.
 
The caravan consists of 3 camels and has a timer.
 
To send a caravan and make a profit, you need to collect and use the specified items.

Each camel needs to be loaded with certain items, and then you can get a reward. 
The reward is listed under each camel.

For example:

The more camels you load, the more rewards you get. You can send the caravan as soon as the "Send" button turns green.

To send it, you need to produce/collect the necessary items, click the "Use" button under them so that the items are written off.
Please note: Only fully loaded camels can be sent.
If you only collected and used one of the required items, you will not receive a reward for that camel.
 
After the timer expires, the caravan is sent automatically. In this case, you will also receive a reward only for fully loaded camels (i.e. for those that have all the items collected and used by pressing the "Use" button).
 
If the caravan is not fully loaded and you try to send it, you will receive the following warning.
 
After successfully sending the caravan, you will receive a reward.
 
Then the countdown to the arrival of the caravan will begin.
 
If you click on the Trading Oasis after the timer expires, three camels with tasks will appear again.